# 民法 / Civil Code — 第四章 (Part 3, Chapter 4) - Law: 民法 (Civil Code), 明治二十九年法律第八十九号 - English title "Civil Code": Ministry of Justice translation - Kind: Act — the distinction between 法律 (Act), 政令 (Cabinet Order), 省令 (Ministerial Order) and 条例 (local ordinance) decides who may issue it and what it may say. - Provision: 第四章 (Part 3, Chapter 4) — address `pt-3/ch-4` - Text in force since: 2026-06-24 - URL (the page that opens at this provision): https://japanlaw.org/ja/civil-code/pt-3/ch-4 - Permanent URL (e-Gov law ID, never renamed): https://japanlaw.org/l/129AC0000000089/pt-3/ch-4 - Every provision below carries its address and both URLs on the line under it. - Japanese text: e-Gov 法令検索, Digital Agency (デジタル庁). English: as marked on each line below. Only the Japanese as published by the government has legal effect; the text below is a copy of it. Every English rendering below is a translation and says which kind: the Ministry of Justice's translation, or this site's machine translation, whose model and date the Sources list names. They are never merged and never substituted for one another. --- ## 第四章　不当利得 — Chapter IV Unjust Enrichment heading: Ministry of Justice translation — Japanese Law Translation Database System pt-3/ch-4 · https://japanlaw.org/ja/civil-code/pt-3/ch-4 · https://japanlaw.org/l/129AC0000000089/pt-3/ch-4 ### 第七百三条（不当利得の返還義務） — (Obligation to Return Unjust Enrichment) caption: Ministry of Justice translation — Japanese Law Translation Database System art-703 · https://japanlaw.org/ja/civil-code/art-703 · https://japanlaw.org/l/129AC0000000089/art-703 **第一項** 法律上の原因なく他人の財産又は労務によって利益を受け、そのために他人に損失を及ぼした者（以下この章において「受益者」という。）は、その利益の存する限度において、これを返還する義務を負う。 art-703/par-1 · https://japanlaw.org/ja/civil-code/art-703/par-1 · https://japanlaw.org/l/129AC0000000089/art-703/par-1 A person that has benefited (in this Chapter referred to as "beneficiary" below) from the property or labor of another person without legal cause and has thereby caused a loss to another person bears the duty to return that benefit, to the extent the benefit exists. Ministry of Justice translation — Japanese Law Translation Database System ### 第七百四条（悪意の受益者の返還義務等） — (Obligation of Beneficiaries in Bad Faith to Return) caption: Ministry of Justice translation — Japanese Law Translation Database System art-704 · https://japanlaw.org/ja/civil-code/art-704 · https://japanlaw.org/l/129AC0000000089/art-704 **第一項** 悪意の受益者は、その受けた利益に利息を付して返還しなければならない。この場合において、なお損害があるときは、その賠償の責任を負う。 art-704/par-1 · https://japanlaw.org/ja/civil-code/art-704/par-1 · https://japanlaw.org/l/129AC0000000089/art-704/par-1 A beneficiary in bad faith must return the benefit received together with interest thereon. In these cases, if any damage still remains, the beneficiary is liable to compensate for this. Ministry of Justice translation — Japanese Law Translation Database System ### 第七百五条（債務の不存在を知ってした弁済） — (Performance Knowing of Absence of Obligation) caption: Ministry of Justice translation — Japanese Law Translation Database System art-705 · https://japanlaw.org/ja/civil-code/art-705 · https://japanlaw.org/l/129AC0000000089/art-705 **第一項** 債務の弁済として給付をした者は、その時において債務の存在しないことを知っていたときは、その給付したものの返還を請求することができない。 art-705/par-1 · https://japanlaw.org/ja/civil-code/art-705/par-1 · https://japanlaw.org/l/129AC0000000089/art-705/par-1 A person that has paid money or delivered anything as performance of an obligation may not demand the return of the money paid or thing delivered if the person knew, at the time, that the obligation did not exist. Ministry of Justice translation — Japanese Law Translation Database System ### 第七百六条（期限前の弁済） — (Performance Before Due Date) caption: Ministry of Justice translation — Japanese Law Translation Database System art-706 · https://japanlaw.org/ja/civil-code/art-706 · https://japanlaw.org/l/129AC0000000089/art-706 **第一項** 債務者は、弁済期にない債務の弁済として給付をしたときは、その給付したものの返還を請求することができない。ただし、債務者が錯誤によってその給付をしたときは、債権者は、これによって得た利益を返還しなければならない。 art-706/par-1 · https://japanlaw.org/ja/civil-code/art-706/par-1 · https://japanlaw.org/l/129AC0000000089/art-706/par-1 If an obligor has paid money or delivered anything as performance of an obligation that has not yet fallen due, the obligor may not demand the return of the money paid or thing delivered; provided, however, that if the obligor tendered anything by mistake, the obligee must return the benefit gained as a result. Ministry of Justice translation — Japanese Law Translation Database System ### 第七百七条（他人の債務の弁済） — (Performance of Obligations of Others) caption: Ministry of Justice translation — Japanese Law Translation Database System art-707 · https://japanlaw.org/ja/civil-code/art-707 · https://japanlaw.org/l/129AC0000000089/art-707 **第一項** 債務者でない者が錯誤によって債務の弁済をした場合において、債権者が善意で証書を滅失させ若しくは損傷し、担保を放棄し、又は時効によってその債権を失ったときは、その弁済をした者は、返還の請求をすることができない。 art-707/par-1 · https://japanlaw.org/ja/civil-code/art-707/par-1 · https://japanlaw.org/l/129AC0000000089/art-707/par-1 If a person that is not an obligor has performed an obligation by mistake and the obligee, acting in good faith, has allowed the instrument to be lost, has damaged the instrument, has waived the security, or has lost the claim by prescription, the person performing the obligation may not demand the return of subject of the performance. Ministry of Justice translation — Japanese Law Translation Database System **第二項** 前項の規定は、弁済をした者から債務者に対する求償権の行使を妨げない。 art-707/par-2 · https://japanlaw.org/ja/civil-code/art-707/par-2 · https://japanlaw.org/l/129AC0000000089/art-707/par-2 The provisions of the preceding paragraph do not preclude the person performing an obligation from exercising the right to reimbursement against the obligor. Ministry of Justice translation — Japanese Law Translation Database System ### 第七百八条（不法原因給付） — (Denial of Claim for Return for Illegal Causes) caption: Ministry of Justice translation — Japanese Law Translation Database System art-708 · https://japanlaw.org/ja/civil-code/art-708 · https://japanlaw.org/l/129AC0000000089/art-708 **第一項** 不法な原因のために給付をした者は、その給付したものの返還を請求することができない。ただし、不法な原因が受益者についてのみ存したときは、この限りでない。 art-708/par-1 · https://japanlaw.org/ja/civil-code/art-708/par-1 · https://japanlaw.org/l/129AC0000000089/art-708/par-1 A person that has paid money or delivered a thing for an obligation for an illegal cause may not demand the return of the money paid or thing delivered; provided, however, that this does not apply if the illegal cause existed solely in relation to the beneficiary. Ministry of Justice translation — Japanese Law Translation Database System --- ## Cites - art-707/par-2: 前項 → 民法 第七百七条第一項 (Article 707, paragraph (1)), art-707/par-1 — https://japanlaw.org/ja/civil-code/art-707/par-1 · https://japanlaw.org/l/129AC0000000089/art-707/par-1 --- ## Sources - e-Gov 法令検索, Digital Agency (デジタル庁) — 民法 — the text in force from 2026-06-24 (https://laws.e-gov.go.jp/law/129AC0000000089/20260624_508AC0000000045), retrieved 2026-10-11 - Japanese Law Translation Database System, Ministry of Justice (法務省) — Civil Code — Ministry of Justice translation (part 1 of 2) (https://www.japaneselawtranslation.go.jp/en/laws/view/4848/tb), retrieved 2026-10-11 - This site's parser, version 190 — 民法 — structure, counts, cross-references and defined terms, computed 2026-10-11