# 民事訴訟法 / Code of Civil Procedure — 第百四十三条 (Article 143) - Law: 民事訴訟法 (Code of Civil Procedure), 平成八年法律第百九号 - English title "Code of Civil Procedure": 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: 第百四十三条 (Article 143)（訴えの変更） — address `art-143` - Text in force since: 2026-06-24 - URL (the page that opens at this provision): https://japanlaw.org/en/code-of-civil-procedure/art-143 - Permanent URL (e-Gov law ID, never renamed): https://japanlaw.org/l/408AC0000000109/art-143 - 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. --- ### 第百四十三条（訴えの変更） — (Amending an Action) caption: Ministry of Justice translation — Japanese Law Translation Database System art-143 · https://japanlaw.org/en/code-of-civil-procedure/art-143 · https://japanlaw.org/l/408AC0000000109/art-143 **第一項** 原告は、請求の基礎に変更がない限り、口頭弁論の終結に至るまで、請求又は請求の原因を変更することができる。ただし、これにより著しく訴訟手続を遅滞させることとなるときは、この限りでない。 art-143/par-1 · https://japanlaw.org/en/code-of-civil-procedure/art-143/par-1 · https://japanlaw.org/l/408AC0000000109/art-143/par-1 As long as it does not fundamentally change the claims, the plaintiff may amend a claim for relief or the statement of the claim until the time that oral arguments reach their conclusion; provided, however, that this does not apply if doing so would substantially delay the litigation proceedings. Ministry of Justice translation — Japanese Law Translation Database System **第二項** 請求の変更は、書面でしなければならない。 art-143/par-2 · https://japanlaw.org/en/code-of-civil-procedure/art-143/par-2 · https://japanlaw.org/l/408AC0000000109/art-143/par-2 The amendment of a claim for relief must be effected by means of a paper document. Ministry of Justice translation — Japanese Law Translation Database System **第三項** 前項の書面は、相手方に送達しなければならない。 art-143/par-3 · https://japanlaw.org/en/code-of-civil-procedure/art-143/par-3 · https://japanlaw.org/l/408AC0000000109/art-143/par-3 The paper document referred to in the preceding paragraph must be served upon the adverse party. Ministry of Justice translation — Japanese Law Translation Database System **第四項** 裁判所は、請求又は請求の原因の変更を不当であると認めるときは、申立てにより又は職権で、その変更を許さない旨の決定をしなければならない。 art-143/par-4 · https://japanlaw.org/en/code-of-civil-procedure/art-143/par-4 · https://japanlaw.org/l/408AC0000000109/art-143/par-4 If the court finds the amendment of the claim for relief or of the statement of the claims to be inappropriate, it must rule against permitting the amendment, upon petition or sua sponte. Ministry of Justice translation — Japanese Law Translation Database System --- ## Cites - art-143/par-3: 前項 → 民事訴訟法 第百四十三条第二項 (Article 143, paragraph (2)), art-143/par-2 — https://japanlaw.org/en/code-of-civil-procedure/art-143/par-2 · https://japanlaw.org/l/408AC0000000109/art-143/par-2 ## Cited by 5 provisions cite this one. No official source publishes this direction. - 民事訴訟法 第百四十三条第三項（訴えの変更） — https://japanlaw.org/en/code-of-civil-procedure/art-143/par-3 · https://japanlaw.org/l/408AC0000000109/art-143/par-3 - 民事訴訟法 第百四十四条第三項（選定者に係る請求の追加） — https://japanlaw.org/en/code-of-civil-procedure/art-144/par-3 · https://japanlaw.org/l/408AC0000000109/art-144/par-3 - 民事訴訟法 第百四十五条第四項（中間確認の訴え） — https://japanlaw.org/en/code-of-civil-procedure/art-145/par-4 · https://japanlaw.org/l/408AC0000000109/art-145/par-4 - 民事訴訟法 第百四十七条第一項（裁判上の請求による時効の完成猶予等） — https://japanlaw.org/en/code-of-civil-procedure/art-147/par-1 · https://japanlaw.org/l/408AC0000000109/art-147/par-1 - 行政事件訴訟法 第十九条第二項（原告による請求の追加的併合） — https://japanlaw.org/en/administrative-case-litigation-act/art-19/par-2 · https://japanlaw.org/l/337AC0000000139/art-19/par-2 --- ## Sources - e-Gov 法令検索, Digital Agency (デジタル庁) — 民事訴訟法 — the text in force from 2026-06-24 (https://laws.e-gov.go.jp/law/408AC0000000109/20260624_508AC0000000046), retrieved 2026-10-17 - Japanese Law Translation Database System, Ministry of Justice (法務省) — Code of Civil Procedure — Ministry of Justice translation (https://www.japaneselawtranslation.go.jp/en/laws/view/4797/tb), retrieved 2026-10-17 - This site's parser, version 209 — 民事訴訟法 — structure, counts, cross-references and defined terms, computed 2026-10-17