The Japanese Civil Code — Overview

Introduction

The Japanese Civil Code (Minpō, Act No. 89 of 1896; Act No. 9 of 1898) is the foundational instrument of Japanese private law. Modelled principally on the first draft of the German Civil Code (Bürgerliches Gesetzbuch) and the French Code civil, it was enacted in three phases over two years: Books I–III (General Provisions, Real Rights, Obligations) in 1896, and Books IV–V (Family, Succession) in 1898. The Code entered into force on 16 July 1898.

The Civil Code is the product of a complex legislative history. The first attempt at codification — the “Old Civil Code” (Kyū Minpō), drafted under French influence — was ready in 1890 but never took effect because of a fierce political and academic controversy known as the Civil Code Dispute (Minpō Ron Sō). The dispute delayed codification and ultimately led to the appointment of a new drafting committee dominated by German-trained jurists, including Nobushige Hozumi, Kenjiro Ume, and Masaaki Tomii.

The Code has undergone two waves of comprehensive reform in the 21st century. The 2004–2005 reform modernised the language of the Code (changing from Classical Chinese to modern Japanese) and revised the provisions on the age of majority, the law of persons, and the law of succession. The 2017 reform was the most substantial revision of the Obligations section (Book III) since the Code’s enactment.

Structure

The Civil Code is divided into five books, reflecting the Pandectist system of the German BGB.

Book I — General Provisions (Articles 1–174). Book I sets out the general principles that apply across the Code. Article 1 proclaims the three fundamental principles: private rights must conform to the public welfare; the exercise of rights and performance of duties must be in good faith (shingi seijitsu); and the abuse of rights (kenri no ran’yō) is prohibited. Book I also contains the law of persons (natural and legal), the law of things (movables and immovables), the law of juridical acts (hōritsu kōi: contracts, declarations of intent, agency, conditions, periods), and the law of prescription (acquisitive and extinctive).

Book II — Real Rights (Articles 175–398). Book II governs rights in rem. The numerus clausus principle (Article 175) provides that no real rights may be created except those recognised by the Civil Code or other laws. The real rights recognised include possession (senyūken), ownership (shoyūken), surface rights (chijōken), servitudes (eichieki-ken), rights of retention (ryūchi-ken), pledges (shichiken), and mortgages (teitōken). Ownership is the most comprehensive right, conferring the exclusive power to use, enjoy, and dispose of property (Article 206), subject to the public welfare and to the rights of others.

Book III — Obligations (Articles 399–724). Book III is the largest book and the one most significantly reformed in 2017. It is divided into five chapters: General Provisions (sources of obligations, performance, non-performance, remedies), Contracts (formation, validity, specific types: sale, exchange, loan, mandate, deposit, partnership, gift, settlement), Tort (fuhō kōi: the general tort clause of Article 709, special torts, damages, limitation), Unjust Enrichment (futō ritoku), and Management of Affairs without Mandate (kanri).

Book IV — Family (Articles 725–881). Book IV governs marriage (formation, effects, dissolution), parental authority, guardianship, and the family register system. The post-war reforms abolished the ie (household) system and established the equality of the sexes in family law.

Book V — Succession (Articles 882–1050). Book V covers the law of inheritance, including the statutory heirs and their shares, wills, estate distribution, and the forfeiture of inheritance rights. The 2018 reform (effective 1 July 2019) introduced significant changes to the surviving spouse’s inheritance rights and the rules on wills.

The 2017 Reform of the Obligations Section

The 2017 reform (Act No. 44 of 2017, effective 1 April 2020) was the most extensive revision of Book III. Its principal features include:

Standard Terms (Yakkan). The reform introduced a new legal framework for standard terms (new Articles 548-2 to 548-4 CC). A party proposing standard terms is deemed to have agreed to them if the other party consents to the contract, unless the terms unreasonably prejudice the other party’s interests in violation of the good faith principle.

Mistake (Mujun). The reform reclassified the effect of mistake from void (mukō) to voidable (torikeshi), aligning Japanese law more closely with German doctrine. The mistaken party may rescind the contract unless the mistake was due to gross negligence.

Warranty Liability (Kashitanpō Sekinin). The reform replaced the warranty liability in sales contracts (formerly Articles 570–572) with a new regime that gives the buyer the right to demand repair, reduction of the purchase price, or damages for non-conformity.

Prescription. The reform unified the limitation periods for contractual and tort claims: the general period is five years from the time the creditor becomes aware of the possibility of exercising the right, with a long-stop of ten years from the time the right accrues.

German and French Influences

The Civil Code is predominantly German in structure and conceptual apparatus. The five‑book system, the distinction between real rights and obligations, the general part, the doctrine of the juridical act — all reflect the influence of the Pandektenwissenschaft as transmitted through the BGB.

French influence is also present, particularly in the law of obligations (the treatment of cause, the concept of lesion, and the rules on unjust enrichment) and in the treatment of the law of persons. The “Old Civil Code” drafted by Gustave Boissonade was French in character, and elements of his draft survived in the enacted Code.

The Civil Code in Context

The Civil Code does not exist in isolation. It is supplemented by a large body of special legislation, including the Commercial Code (Shōhō), the Companies Act (Kaisha Hō), the Trust Act (Shintaku Hō), the Consumer Contract Act (Shōhisha Keiyaku Hō), and the Product Liability Act (Seizōbutsu Sekinin Hō). The Supreme Court’s case law — particularly its development of the good faith and abuse of rights doctrines — has been instrumental in adapting the Code to changing social and economic circumstances.

The Code’s longevity and its successful adaptation to Japan’s development from an agrarian economy to a post-industrial society attest to the skill of its drafters and the flexibility of the civilian tradition on which it rests. The 2017 reform demonstrates Japan’s continuing commitment to modernising its private law while preserving its civilian identity.