Product Liability & Safety 2026 Comparisons

Consumer Products

Consumer Product Safety Act

The principal legislation governing product safety in Japan is the Consumer Product Safety Act (CPSA), which regulates products intended primarily for ordinary use by general consumers (“Consumer Products”) from the perspective of physical safety.

The regulation under the CPSA primarily consists of two categories: ex ante (preventive) regulation aimed at preventing product incidents, and ex post regulation, addressing incidents once they have occurred.

Ex ante regulation works as follows. Consumer products that carry a risk of harm (eg, lighters, laser pointers, and kerosene heaters) are designated as “Specified Products”. Manufacturers and importers of Specified Products are required to comply with technical standards prescribed by the government. Manufacturers or importers may affix a mark, or the Product Safety of Consumer Products mark (the “PSC mark”), to products that conform to those technical standards, whilst retailers are prohibited from selling Specified Products that do not bear the PSC mark.

On the other hand, with respect to ex post regulation, manufacturers and importers are obliged to report serious product incidents, such as deaths and fires, to the Consumer Affairs Agency (CAA) within ten days of becoming aware of the incident. This obligation is addressed further in 1.4 Obligations to Notify Regulatory Authorities.

Household Products Containing Harmful Substances Control Act

The Household Products Containing Harmful Substances Control Act (HPCA) is another law regulating Consumer Products from the perspective of chemical safety.

The HPCA provides for the prevention of health hazards caused by chemical substances contained in products. At present, 21 substances that have been established to cause harm to health are subject to this regulation.

Electrical Appliances and Materials Safety Act, Gas Business Act, and Act on the Securing of Safety and the Optimisation of Transaction of Liquefied Petroleum Gas

Electrical appliances, gas appliances and liquefied petroleum gas appliances, which fall within the category of Consumer Products, are subject to specific special acts. The Electrical Appliances and Materials Safety Act, Gas Business Act, and Act on the Securing of Safety and the Optimisation of Transaction of Liquefied Petroleum Gas are, together with the CPSA, collectively referred to as the “Four Product Safety Acts”.

Non-Consumer Products

In Japan, certain products are excluded from the scope of Consumer Products which are subject to the CPSA. Instead, such products are subject to regulation under specific acts. The following are some examples.

Food Sanitation Act

The Food Sanitation Act (FSA) provides regulations from a public health perspective to ensure food safety. As to ex ante regulation, business operators engaged in activities that significantly impact public health (eg, restaurants) are required to obtain a permit after meeting the prescribed facility standards. Under the FSA, the sale of unsanitary foods is prohibited. In addition, foods, additives and related products for which standards, manufacturing requirements, labelling requirements, and ingredient specifications are established must not be sold if they do not conform to those requirements or standards.

In respect of ex post regulation, the regulatory authorities may order necessary measures, such as disposal of food that has caused an incident, in order to prevent the spread of harm and the recurrence of similar incidents after an incident has occurred.

Pharmaceuticals and Medical Devices Act

The Pharmaceuticals and Medical Devices Act (PMDA) regulates pharmaceuticals, quasi-pharmaceutical products, cosmetics, medical devices and regenerative medical products for public health by ensuring their quality, efficacy and safety. These products are subject to more stringent regulation than other products at every stage, including development, approval, manufacturing, distribution and use, because of their inherent nature of containing both efficacy effects and side effects.

Road Transport Vehicles Act

The Road Transport Vehicles Act (RTVA) provides for systems for the registration and inspection of vehicles and provides regulations concerning vehicle maintenance in order to ensure their safety and promote their proper use. Under the RTVA, as an ex ante regulation, motor vehicles must be confirmed to comply with the safety standards prescribed by the government and are required to be registered before being put into use on the road. In addition, as an ex post regulation, the government may recommend that manufacturers take corrective measures, including the implementation of recalls.

Other Laws – Consumer Safety Act

The Consumer Safety Act (CSA) provides for the collection of information on consumer incidents and for measures to prevent the occurrence and spread of consumer harm in order to prevent harm to consumers and ensure their safety. Because the CSA was enacted in connection with the establishment of the CAA, the CSA primarily defines the roles and functions of the Agency. Nevertheless, the CSA also provides for measures such as recommendations and orders issued to business operators, as well as prohibitions or restrictions on transfer and orders for product recalls. In this sense, it serves as a safety net for situations in which it is difficult to respond under the individual acts described above.

The Ministry of Economy, Trade and Industry (METI) is the principal regulatory authority for products subject to the Four Product Safety Acts. The CAA also plays an important role with respect to the reporting and publication of serious product incidents.

Manufacturers and importers of products subject to the Four Product Safety Acts may file a business notification with METI. In addition, if they fulfil obligations such as conducting inspections for compliance with technical standards and preparing and retaining inspection records, they may affix specific marks, such as the PSC mark under the CPSA, to their products.

In order to verify whether notified businesses are properly fulfilling their legal obligations, METI conducts “market surveillance testing”, whereby products in circulation on the market are purchased at random and inspected. Where a non-conforming product is identified in the course of such testing, METI directs the notified business of that product to take corrective measures and implement preventive measures to avoid recurrence. If necessary, METI may take administrative actions under the Four Product Safety Acts, including improvement orders, prohibition of affixing the applicable marks (which in practice amounts to a suspension of shipment and sale), and orders to prevent harm. Furthermore, METI may order the business to take corrective measures, including the implementation of product recalls.

The CAA was established in 2009 to promote the administration of consumer protection in a unified manner. Under the reporting and publication system for product incident information under the CPSA (see 1.4 Obligations to Notify Regulatory Authorities), the Agency receives and publishes reports of serious product incidents. The CAA may also order manufacturers or importers that have failed to report serious product incidents to establish the internal systems necessary for appropriately collecting, managing, and providing incident information.

Certain products are regulated by other authorities. For example, with respect to products that fall outside the scope of the CPSA as described in 1.1 Product Safety Legal Framework:

• the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has jurisdiction over motor vehicles; and
• the Ministry of Health, Labour and Welfare (MHLW) has jurisdiction over pharmaceuticals, cosmetics, medical devices, food and food additives.

These regulatory authorities exercise the powers set out in individual laws. For example, these authorities may establish technical standards and other related requirements and order manufacturers to take corrective measures, including the implementation of recalls.

Under the Acts described below, if a regulatory authority issues an order to take corrective measures, the relevant business operators are obliged to commence those measures. In practice in Japan, however, it is common for business operators to take corrective and other measures voluntarily, without awaiting such order from the regulatory authority. Therefore, it is rare for regulatory authorities to issue orders for corrective measures. For example, under the CPSA, only three orders have been publicly disclosed to date. The following paragraphs focus on voluntary corrective measures.

CPSA

Manufacturers and importers of consumer products have certain “best-effort” obligations. First, if a product incident has occurred in connection with consumer products they have manufactured or imported, they are obliged to make efforts to investigate the cause of the incident. In addition, when they consider it necessary to prevent the occurrence and spread of harm, they are obliged to make efforts to take measures to prevent such harm, such as recalling the relevant consumer products. Accordingly, where a product incident occurs that may cause or worsen personal injury to consumers, manufacturers and importers are expected to conduct product recalls in a timely manner.

In practice, when manufacturers or importers implement product recalls, they usually refer to guidelines, such as the Recall Handbook for Consumer Products issued by METI in 2022, and provide information to consumers accordingly.

Food Sanitation Act

Food business operators also have certain “best-effort” obligations. First, in order to prevent public health hazards caused by the foods they sell, they are obliged to make efforts to provide prescribed records to the national government, prefectures and other relevant authorities. In addition, they are obliged to make efforts to promptly and appropriately take necessary measures such as disposing of or otherwise handling foods that have caused food sanitation hazards. Where an operator recalls food that violates the FSA, or food that is suspected of violating that FSA, the operator must notify the prefectural governor without delay of the commencement of the recall and the progress thereof.

PMDA

Holders of marketing approval for pharmaceuticals, quasi-drugs, cosmetics, medical devices or regenerative medical products, as well as operators granted special approval for foreign manufacturing of such products, are required to take the following measures. If they become aware that the use of the relevant product may cause or is likely to cause harm to public health or may lead to its spread, they must take necessary measures to prevent such harm or its spread, including disposal, recall, suspension of sales, and provision of information. When they conduct recalls, they must report to the MHLW the commencement of the recall and the progress thereof. In addition, they are expected to promptly provide recall information to medical institutions and other relevant parties, and to disseminate all recall information using the internet.

Road Transport Vehicles Act

Automobile manufacturers and other related business operators must notify the MLIT when they implement recalls in cases where vehicles do not comply with, or are likely to cease complying with, the safety standards for road vehicles and where the cause is deemed to lie in the design or manufacturing process. In addition, when automobile manufacturers or related business operators file a recall notification, they are required to promptly inform the users of the recalled vehicles about the details of the recall through mail, direct visits, or other means. They are also required to publish the notification in the official journal of the Japan Automobile Service Promotion Association and other relevant media, thereby ensuring automobile maintenance businesses are also informed of the recall information. Even if vehicles are not in a state of non-compliance with safety standards, automobile manufacturers or related operators may implement an improvement measure where they determine that the vehicle is, or is likely to become, in a condition that cannot be left unaddressed from the standpoint of safety or accident prevention. Finally, in cases that do not fall under a recall or an improvement measure, the automobile manufacturers and related business operators may also implement a measure known as a service campaign.

CPSA

Where manufacturers or importers become aware that a serious product incident has occurred in connection with the consumer products they manufacture or import, they are required to report to the CAA within ten days of becoming aware of the incident: the name and model of the relevant consumer product, the details of the incident, and the quantities manufactured or imported and sold. This report must be made in Japanese using the prescribed reporting form.

“Serious product incidents” mean product incidents in which serious harm has occurred or may occur, such as a fatality, serious injury or illness, permanent disability, carbon monoxide poisoning, or fire.

In addition, although it is not a legal obligation, the manufacturers or importers are also encouraged to report less serious incidents that do not fall within serious product incidents (“non-serious product incidents”) to the National Institute of Technology and Evaluation (NITE). Thus, reporting under the CPSA is accident-based rather than risk-based.

Food Sanitation Act

Under the FSA, certain food ingredients and substances are designated as those that require special attention from the perspective of preventing public health hazards. Business operators handling foods containing such ingredients or substances must promptly submit a notification to the prefectural governor without delay, using the prescribed form, when they obtain information indicating that such foods have caused or may cause harm to human health. Business operators engaged in the manufacture, processing, or sale of food or food additives are under a best-efforts obligation to provide to the prefectural governor or other authority information relating to health hazards attributable to their products (limited to cases where a physician has diagnosed the symptoms as caused by, or suspected to be caused by, the relevant food or additive) and information regarding violations of law.

In addition, business operators approved for Food for Specified Health Uses and notifiers of Foods with Function Claims are obliged to collect information on health hazards (as defined above). Furthermore, when they obtain information indicating a risk of occurrence or spread of such health hazards, they must promptly provide that information to the prefectural governor and other relevant authorities.

PMDA

Marketing authorisation holders are required to report to the MHLW, through the Pharmaceuticals and Medical Devices Agency (PMDA), any adverse reactions or similar events relating to the efficacy and safety of a product where a causal relationship cannot be clearly excluded. Reporting deadlines differ depending on the severity of the adverse reactions or infections and whether they were previously known. The reporting needs to be made in prescribed forms. Reporting under the PMDA is also accident-based.

CPSA

A person who sells a specified product without affixing the PSC mark, or who contravenes an order issued by the competent authority, including a labelling order, business suspension order, recall order, or corrective order, may be subject to imprisonment for up to one year, a fine of up to JPY1 million, or both.

If manufacturers or importers of relevant products fail to fulfil the obligation to report serious product incidents to the regulatory authority (see 1.4 Obligations to Notify Regulatory Authorities), they are not immediately subject to penalties. The penalties may be imposed when manufacturers or importers subsequently contravene an order to establish an internal system, and include imprisonment for up to one year, a fine of up to JPY1 million, or both. When the violation is committed by a corporation, both the individual perpetrator and the corporation itself are subject to a fine of up to JPY1 million.

Criminal penalties also apply for violations of recall orders or other orders under the PMDA, the RTVA and the FSA. For example, a person who contravenes a recall order or other order under the PMDA may be subject to imprisonment for up to three years, a fine of up to JPY3 million, or both; when the violation is committed by a corporation, the corporation is also subject to a fine of up to JPY100 million. A person who contravenes a recall order or other order under the RTVA may be subject to imprisonment for up to one year, a fine of up to JPY3 million, or both; where the violation is committed by a corporation, the corporation is also subject to a fine of up to JPY200 million.

The main causes of action in product liability claims are tort, product liability and contract.

Tort

The general law of tort is provided in the Civil Code. The elements necessary to establish a tort are as follows:

• infringement of the plaintiff’s right or legally protected interest;
• intention or negligence on the part of the defendant;
• the occurrence of damage; and
• a causal relationship between the infringement and the damage.

Product Liability Act

The Product Liability Act is a special tort law under the Civil Code. The elements necessary to establish a claim under the Product Liability Act are as follows:

• the defendant is a manufacturer, etc;
• the subject matter is a product;
• the existence of a defect;
• the occurrence of damage; and
• a causal relationship between the defect and the damage.

Intent or negligence of a manufacturer, etc is not required.

Manufacturer, etc

A manufacturer, etc, includes not only a person who manufactures the product in the course of business, but also an importer, a person who has displayed its name on the product as the manufacturer, and any other person who may be regarded as the de facto manufacturer. A manufacturer, etc, does not include a mere retailer.

Product

A product means movable property that has been manufactured or processed. A product does not include any intangible property (eg, software and artificial intelligence), immovable property, or unprocessed movables (eg, agricultural produce, marine products and livestock products).

Defect

A defect means a lack of safety ordinarily expected of the product. The Product Liability Act provides the following factors to determine whether the product is defective:

• the characteristics of the product;
• the normally foreseeable use of the product;
• the timing of delivery of the product; and
• other circumstances relating to the product.

In academic discussion, defects are generally classified into three categories:

• manufacturing defect;
• design defect; and
• warning defect.

These categories are not expressly listed in the Product Liability Act; in practice, however, the court often determines the existence of defects by reference to these categories.

Damage

Recoverable damage includes harm to life, body and property. Non-pecuniary loss, including solatium, is also recoverable. However, the Product Liability Act does not apply to cases where damage is limited solely to the defective product.

Causal relationship

It must be established that the damage was caused by the defect in the product.

Contract

Where a purchased product is non-conforming (ie, defective), the buyer may claim damages against the seller. The elements necessary to establish a claim for damages are as follows:

• the existence of a contract;
• a non-conformity (ie, defect) in the product;
• the occurrence of damage;
• a causal relationship between the non-conformity and the damage; and
• fault attributable to the seller.

Of the above elements, the buyer is not required to prove fault attributable to the seller. The seller must establish that no fault is attributable to it in order to avoid responsibility; in other words, absence of attributable fault operates as a defence.

The following persons may bring product liability claims. For standing in collective redress, see 2.16 Existence of Class Actions, Representative Proceedings or Co-Ordinated Proceedings in Product Liability Claims.

Tort

Both consumers and business operators may bring claims. No contractual relationship is required.

Product Liability Act

Both consumers and business operators may bring claims. No contractual relationship is required.

Contract

Both consumers and business operators may bring claims. A contractual relationship is required.

Tort

A claim for damages in tort is extinguished by prescription if it is not exercised within three years from the time when the victim or the victim’s legal representative became aware of the damage and the identity of the tortfeasor. Where harm to life or body is involved, the limitation period is extended to five years. In all cases, the claim is also extinguished when 20 years have elapsed from the date of the tort.

Product Liability

A claim for damages under the Product Liability Act is extinguished by prescription if it is not exercised within three years from the time when the victim or their legal representative became aware of the damage and the identity of the entity liable therefor. Where harm to life or body is involved, the limitation period is extended to five years. The claim is also extinguished when ten years have elapsed from the date on which the manufacturer, etc, delivered the product.

Contract

In order to bring a claim based on contractual liability, the buyer must notify the seller of the non-conformity within one year from the time when the buyer became aware of the non-conformity. Failure to give such notice precludes the buyer from bringing a claim based on the non-conformity unless the seller was aware of the non-conformity at the time of delivery or was unaware of it because of gross negligence.

A claim for damages based on contractual liability is extinguished by prescription if it is not exercised within five years from the time when the buyer became aware that the claim could be exercised. Furthermore, the claim is also extinguished when ten years have elapsed from the date when the claim became exercisable. Where harm to life or body is involved, the limitation period is extended to 20 years.

Whether Japanese courts have jurisdiction is generally determined based on the international jurisdiction provisions of the Code of Civil Procedure, and there are no jurisdictional rules specific to product liability claims. The courts have jurisdiction in the following circumstances.

In All Cases

Where a corporation’s principal office or business office is located in Japan.

Where the representative or person in charge of business is domiciled in Japan, if the corporation has no office in Japan or its location is unknown.

Tort and Product Liability

Where the place of the tort or the place where the damage occurred is in Japan.

In product liability cases, the place of the tort is generally understood as the place where the product was manufactured. Where damage occurs in Japan because of a defect in a product manufactured outside Japan, Japanese courts do not have jurisdiction unless such damage was ordinarily foreseeable.

Contract

Where the place of performance of the relevant obligation as specified in the contract is located in Japan.

Where, under the law of the place chosen in the contract, the place of performance of the relevant obligation is located in Japan.

In Japan, there are no mandatory pre-action procedures or requirements that must be followed before the commencement of civil proceedings in product liability cases.

In civil proceedings in Japan, there is no rule under which parties are required to preserve evidence, either before or after the commencement of civil proceedings, including any obligation equivalent to a litigation hold in the United States.

On the other hand, there is a procedure under which a party may apply to the court for the preservation of evidence held by opposing parties or third parties to prevent the loss or destruction of evidence. A party may apply for the preservation of evidence either before or after the commencement of civil proceedings; however, such application must be based on a finding that there are circumstances where it will be difficult to use the evidence unless the examination of the evidence is conducted in advance.

In Japan, there is no procedure for broad-ranging disclosure of evidence equivalent to discovery in the United States; the following are examples of mechanisms related to evidence disclosure under Japanese law.

Inquiry by a Bar Association

An inquiry by a bar association is a procedure under which an attorney, in connection with a case they had been retained for, conducts inquiries through a Bar association by requesting necessary information from public authorities, companies and other organisations. An attorney may use this procedure either before or after the commencement of civil proceedings. The Supreme Court has confirmed that recipients of such inquiries are under a duty to respond; however, there is no sanction for refusal.

Inquiry by a Party

An inquiry by a party is a procedure under which a party makes written inquiries of the opposing party concerning matters necessary for the preparation of arguments and evidence. A party may use this procedure either before or after the commencement of civil proceedings. It is also generally understood that the other party is under a duty to respond; however, there is no sanction for refusal.

Preservation of Evidence

Preservation of evidence as described in 2.6 Rules for Preservation of Evidence in Product Liability Claims is used, especially in medical malpractice cases, as a means not only to prevent the loss or destruction of evidence but also to make the opposing party disclose the relevant evidence, either before or after the commencement of civil proceedings; however, in product liability proceedings, this procedure appears not to be commonly used.

Commission of Sending of Documents

Commission of sending of documents is a procedure under which a party applies to the court to request the holder of a specific document, whether the opposing party or a third party, to send the document to the court. A party may apply for this procedure only after the commencement of civil proceedings. It is generally understood that the holder of the document is under a duty to comply; however, there is no sanction for refusal to do so.

Order to Submit Documents

An order to submit documents is a court order requiring the holder of a specific document, whether the opposing party or a third party, to submit it. A party may apply for this procedure only after the commencement of civil proceedings. The holder of the document is under a duty to comply. Where the holder is the opposing party and fails to comply with the order, the court may deem the applicant’s assertions regarding the contents of the document to be true. Where the holder is a third party and fails to comply with the order, the court may impose a non-criminal monetary fine of up to JPY200,000.

In Japan, there are no rules for expert evidence specific to product liability cases; the general rules in civil proceedings are applied.

Private Expert

A party may produce an expert opinion written by an individual whom the party selects and retains, for the purpose of establishing specialised expertise. A party may also apply to the court for witness examination of an expert whom the party also selects and retains. Such evidentiary activities are widely undertaken in practice so that parties are able to select the individuals they consider most suitable to support their claims.

Court-Appointed Expert

A party may apply to the court for an expert examination by a court-appointed expert for the purpose of establishing specialised expertise. The opinion of the court-appointed expert constitutes evidence. Whilst the court is not strictly bound by the expert’s opinion under the principle of free evaluation of evidence, it has, in practice, a significant influence on the court’s findings.

Technical Advisers and Conciliation Commissioners

A technical adviser is an expert appointed by the court in order to provide explanations based on specialised expertise. The technical adviser serves in an advisory capacity, supplementing knowledge that the court may lack; however, the technical adviser’s explanations themselves do not constitute evidence.

By way of exception, the court may appoint an adviser with specialised expertise as a mediation commissioner after converting the litigation proceedings into mediation proceedings. In such a case, the court may form its conviction based on the specialised expertise of the adviser, or mediation commissioner.

General Principle

As described in 2.1 Product Liability Causes of Action and Sources of Law, the principal causes of action in product liability claims are tort, product liability and contract. In all three types of causes of action, the burden of proving the facts constituting the cause of action lies with the plaintiff (ie, the victim). The burden of proof in respect of defences (see 2.12 Defences to Product Liability Claims) lies with the defendant (eg, a manufacturer, etc).

The required standard of proof is, as under the general principle of civil proceedings, a high degree of probability, exceeding the balance of probabilities.

Factual Presumption Under the Product Liability Act

As noted above, in proceedings for damages under the Product Liability Act, the plaintiff bears the burden of proving the facts constituting the cause of action. There is no provision for a shifting of the burden of proof or a statutory presumption in respect of the existence of a defect or causation between a defect and damage.

Nonetheless, in practice, the court has substantially reduced the burden on plaintiffs in many cases by applying a “factual presumption” for a defect or causation or both. A “factual presumption” refers to the process by which the court, based on free evaluation of evidence, infers the existence of one fact from another. For example, if a product accident occurred whilst a victim used the product in an ordinary manner, the court often presumes that the product is defective. In such cases, the plaintiff (ie, the victim) is not required to prove the details of the defect or the scientific mechanism of the accident, whilst the defendant (ie, the manufacturer, etc) is required to establish facts to rebut the presumption, such as another cause of the accident.

Although a factual presumption is merely an inferential step in the court’s fact-finding process, once such a presumption is drawn, it is not easy for the defendant to rebut it. As a result, in cases where a factual presumption is established, the plaintiff’s claim is often upheld. Accordingly, in many product liability cases, the structure of the dispute is such that the plaintiff argues and proves that there was no problem with the use or management of the product, whilst the defendant counterargues that the product was used in an unanticipated manner.

There are no specialised courts dedicated to product liability proceedings; such cases are heard by the ordinary civil courts, namely the District Courts and the Summary Courts.

Claims not exceeding JPY1.4 million are in principle heard by the Summary Courts, whilst all other claims are heard by the District Courts. However, product liability proceedings generally require specialised expertise and involve complex arguments and evidence, making them ill-suited to the expeditious procedures of the Summary Courts. Accordingly, even where the amount of the claim does not exceed JPY1.4 million, cases may at the court’s discretion be heard by the District Courts.

In Japan, since there is no jury system for civil proceedings (in contrast, in criminal proceedings, there is a lay judge system where members of the public participate in certain types of cases), product liability proceedings are conducted solely before professional judges.

In Japan, civil proceedings operate based on a three-tier system of appeals. In product liability proceedings, as in ordinary civil proceedings, a party that has been wholly or partially unsuccessful may appeal, first to the High Court and thereafter to the Supreme Court.

First Appeal

The first appeal is heard by the High Court. As this is a full rehearing on both fact and law, the appellant may raise any point of alleged error or improper assessment in the first instance judgment, including errors in fact-finding and misapplication of law.

A notice of appeal must be filed at the court of first instance within 14 days of receipt of the first instance judgment. The notice of appeal need not contain detailed grounds; it suffices to file a document stating that the party intends to appeal. The detailed grounds of appeal are set out in a statement of reasons for appeal (ie, an appellate brief), which is required to be filed within 50 days of the filing of the notice of appeal under the Rules of Civil Procedure; however, the appeal will not be dismissed for that reason even if the appellate brief is filed after the deadline.

Second Appeal

The second appeal, or the final appeal, is heard by the Supreme Court. The Supreme Court reviews questions of law only; it does not conduct its own fact-finding but decides based on the findings of fact made by the lower courts.

A notice of appeal must be filed at the court of second instance within 14 days of receipt of the second instance judgment. An appeal to the Supreme Court lies only where the judgment is contrary to the Constitution or where there is a material procedural irregularity. The Supreme Court may also accept a case for review on the application of a party if the case is considered to involve an important question concerning the interpretation of a statutory provision.

The notice of appeal need not contain detailed grounds; it suffices to file a document stating that the party intends to appeal. The detailed grounds are set out in a statement of reasons for final appeal (ie, final appellate brief), which must be filed within 50 days of service of the notice of acceptance of the appeal. Failure to file the final appellate brief within the prescribed period will result in the dismissal of the application.

In product liability cases, a defendant may assert general defences in civil proceedings, such as statute of limitations and contributory negligence.

Especially in cases of contractual liability, as described in 2.1 Product Liability Causes of Action and Sources of Law, a defendant (ie, a seller) is held not responsible for damages by establishing that no fault is attributable to it.

In addition, especially in civil proceedings for damages under the Product Liability Act, the following defences are available to a defendant (ie, a manufacturer, etc).

Development Risks Defence

A manufacturer, etc, is held not responsible for damages by establishing that the defect in the product could not have been recognised in light of the state of the scientific or technical knowledge at the time of the delivery of the product. The Supreme Court has confirmed that the “state of the scientific or technical knowledge” refers to the highest level of scientific or technical knowledge available anywhere in the world at that time. Given this exceptionally high standard, there have been no cases, at least based on publicly available information, where the development risks defence has been successfully established.

Component or Raw Material Manufacturer's Defence (Design Instruction Defence)

Whilst a manufacturer, etc, of a component or a raw material is generally held responsible for damages when the product incorporating the component or raw material is defective due to a defect of the component or raw material, it may be exempt from liability by establishing that the defect arose solely as a result of compliance with design instructions by the manufacturer, etc, of the product and the component or material manufacturer was not at fault in causing the defect in accordance with the instruction by the product manufacturer, etc. Given the difficulty of establishing a lack of fault, there have been no cases, at least based on publicly available information, where such component or raw material manufacturer’s defence has been successfully established.

In Japan, there is no mechanism whereby compliance with regulatory requirements automatically confers immunity from liability. There is no provision to the effect that a regulatory violation gives rise to a presumption of a defect, either.

Whether liability in damages arises is assessed against the elements of the relevant cause of action (see 2.1 Product Liability Causes of Action and Sources of Law). The content of the applicable regulatory requirements and whether those requirements have been complied with are among the circumstances taken into account when assessing the existence of a defect. As a result, regulatory non-compliance is more likely to lead to a finding of liability.

The same applies to guidelines and industry standards voluntarily established by trade associations.

Litigation Costs

As a general rule, litigation costs are borne by the losing party. In the event of partial success by both parties, the court has discretion to determine the proportion of costs borne by each party.

Litigation costs primarily include the court filing fee, travel expenses, daily allowances and accommodation costs incurred in attending hearings, the costs of preparing and filing documents submitted to the court, and the travel expenses and daily allowances of witnesses and court-appointed experts. Litigation costs do not include the cost of preparing private expert opinions or remuneration paid to private experts retained by a party. The recoverable amounts as costs are prescribed by law on a standardised basis.

In order to recover costs, a prevailing party must initiate proceedings to determine the amount of the costs after the judgment becomes final and binding. Given the complex and administrative burden of this procedure, prevailing parties often refrain from undertaking it in practice.

Legal Fees

As a general rule, the costs for which the losing party is liable do not include the legal fees incurred by the other party; accordingly, legal fees are in principle borne by the party that incurred them.

However, in claims under the Product Liability Act or in tort claims under the Civil Code, a portion of the prevailing party’s legal fees (generally in the order of 10% of the damages awarded) may be included in the award of damages. In the context of contractual claims, it is not usual for legal fees to be included as part of the damages awarded to the prevailing party.

In Japan, there are no rules for litigation funding specific to product liability cases; general rules are applied.

In general, the arrangement of legal fees is typically either an initial retainer combined with a success fee or a time-based fee arrangement, although a fully contingent fee arrangement is not prohibited.

With respect to litigation funding by a third party, there is a public scheme, the civil legal aid scheme, in which the Japan Legal Support Centre advances legal fees. Users repay them after the resolution of the case.

Recently, some business operators provide services where they advance legal fees and are repaid by receiving a certain proportion of any recovery as a success fee upon resolution of the case; however, there is debate as to whether third-party litigation funding, depending on the structure of the arrangement, may fall foul of the prohibition on unauthorised legal practice under the Attorneys Act or the prohibition on litigation trusts under the Trust Act.

Crowdfunding is also available, and several platforms have been established. It is often used particularly in the fields of administrative litigation, criminal trials and public interest litigation. Donation-based crowdfunding, where financial returns to supporters are not anticipated, is the predominant model; investment-based crowdfunding, where investors receive a share of any recovery, has not been widely adopted.

In Japan, there is a form of opt-in collective proceedings under the Act on Special Measures Concerning Civil Court Proceedings for the Collective Redress for Damage Incurred by Consumers. This procedure is often referred to as the Japanese-style class action. The procedure under this Act operates in two stages:

• in the first stage, a designated consumer organisation brings proceedings against a business operator, in which it is determined whether the business operator is under a general liability to pay damages to a number of affected consumers; and
• in the second stage, for each consumer who belongs to the class confirmed by the first-stage judgment and has opted in, it is determined, through a simplified procedure, whether the consumer is entitled to payment and, if so, the extent of such entitlement.

However, in practice, this procedure is unlikely to be used for product liability claims.

This is partly because claims that may be brought under this procedure are limited to claims relating to consumer contracts including contractual claims and claims for damages in tort within a strictly defined scope; claims for damages under the Product Liability Act are excluded. In addition, claims under this procedure are primarily limited to the value of the purchase price of the product, and may not extend to consequential damage, loss of profits, or damage arising from harm to life or body.

Instead, where a number of victims are affected, multiple victims may jointly file lawsuits, which may be consolidated for hearing. Such group litigation, or mass tort litigation, is no more than the joinder for consolidated hearing of individual actions brought by each victim, that is, there is no mechanism whereby victims are compulsorily brought into proceedings as parties; however, plaintiffs often try to establish frameworks similar to a class action by requesting courts and defendants to enter into a comprehensive settlement scheme covering all victims, not merely those who are parties to the proceedings.

In Japan, there is only one Supreme Court judgment in which the court has presented a substantive interpretation of product liability. This case was a widely publicised mass tort litigation, in which the plaintiffs were, among others, the bereaved families of patients who died due to side effects of a lung cancer drug, and the defendants were the pharmaceutical company, which the author firm represented, and the Japanese government. The main issue in the case was the existence of a design defect and warning defect. In 2013, the Supreme Court held that no defect existed, stating with respect to warning defects that it was sufficient for manufacturers to provide warnings regarding risks that were foreseeable based on scientific or technical knowledge at the time of delivery. This aligns with the definition of warning defects under the Restatement (Third) of Torts in the United States.

Another significant case is a mass tort litigation, in which patients who developed wheat allergies after using a wheat-containing soap claimed for damages against the seller, manufacturer, and raw material supplier. There were numerous issues in this case: for example, the High Court held in 2018 that the seller of the soap was a de facto manufacturer based on the facts, such as the seller’s registration of the trade mark, statements in brochures indicating that the seller was the product developer, and the fact that manufacturing equipment owned by the seller was used by the manufacturer. The court also addressed issues including the relevant point in time for determining defects, the development risk defence, and the factors to be considered in assessing defects in generic products.

There are also several significant cases with respect to the burden of proof as described in 2.9 Burden of Proof in Product Liability Cases. For example, in a case where a victim suffered a low-temperature burn caused by prolonged use of a mobile phone inside a Japanese kotatsu, a heated table with a blanket, the High Court held in 2010 that, whilst the plaintiff bore the burden of proving the existence of a defect, given circumstances such as the occurrence of the accident during normal use, the fact that the mobile phone was the cause of the burn, and the occurrence of abnormal overheating of the phone, it was possible to infer the existence of a defect, even in the absence of specific proof regarding the details of the defect or the mechanism of the overheating. In another case concerning damage to a house caused by a fire, the High Court held in 2020 that based on facts such as the burn patterns on an air conditioner’s outdoor unit and the situation immediately following the outbreak of the fire, it was possible to infer both the existence of a defect and the causal relationship between the defect and the fire, even without specific proof regarding the details of the defect or the mechanism of the fire.

Among more recent significant cases, there is a High Court judgment concerning the death of a nine-month-old infant who became trapped between a bed guard and a mattress. In this case, although warnings prohibiting use for infants under 18 months of age were included in the instruction manual, the court held that the bed guard was defective based on the fact that the warning was not displayed on the product itself.

Product Safety

The amendments to the Four Product Safety Acts came into force on 25 December 2025. The principal content of the amendments is as follows. For further details, see the Japan Product Liability & Safety 2026 Trends and Developments section of this Guide.

Strengthened Regulation of Overseas Business Operators

In respect of overseas business operators selling through digital platforms (DPF) operated by other companies, and overseas business operators selling through their own Japan-facing websites, obligations have been introduced under the legislation in relation to Specified Products, including a duty to comply with technical standards; a prohibition on selling products without the conformity marking; and an obligation to appoint a domestic administrator.

Responsibilities of DPF providers

Regulatory authorities are now empowered to request DPF providers, which provide a platform for transactions aimed at Japanese consumers, to take measures such as removing listed products.

Regulation of Specified Products for Children

Under the CPSA, manufacturers and importers of products used primarily by children that are designated by Cabinet Order are now under an obligation to comply with technical standards and age-of-use standards and to display the PSC mark or equivalent.

Product Liability

In Japan in recent years, a number of judgments have addressed the obligations of DPF providers in relation to products listed on their platforms. Specific cases are discussed in the Japan Product Liability & Safety 2026 Trends and Developments section of this Guide; on the basis of the reasoning in these judgments, it appears that a DPF provider would not necessarily be liable for damage caused to a purchaser simply because a product with a safety issue was listed and sold on its platform, but it may be exposed to liability where it continued to list a product whose specific danger it was aware of without removing it from the platform, thereby causing harm to the victim.

In Japan, in recent years, discussions have been conducted on product safety and product liability in relation to software, including AI, and various guidelines have been published.

For example, the Act on the Promotion of Research, Development, and Utilisation of Artificial Intelligence–Related Technologies (commonly referred to as the “AI Act”) was enacted in 2025 in order to promote AI innovation while addressing associated risks. In 2026, the AI Business Operator Guideline was revised, which sets out the basic principles regarding the measures required for AI development, provision and use. The guideline defines the responsibilities of AI developers, AI providers and AI users, taking into account not only generative AI but also AI agents and physical AI. The Guideline on Technical Measures for Ensuring AI Security was also issued in 2026, which specifically addresses the need to ensure AI security.

With respect to cybersecurity, multiple guidelines have been issued, including the Cybersecurity Management Guideline. In 2025, the operation of the Labelling Scheme based on Japan Cyber-Security Technical Assessment Requirements (JC-STAR) began, which addresses cybersecurity for IoT devices.

The Product Liability Act is also currently under review by the CAA. The CAA has conducted research and hearings about the contents and impact of the new Product Liability Directive in the European Union on the Product Liability Act in Japan. In addition, with respect to AI in particular, METI has examined issues relating to civil liability, and in 2026, the Guideline on the Interpretation and Application of Civil Liability in the Use of AI was published.

For further details, see the Japan Product Liability & Safety 2026 Trends and Developments section of this Guide.