Junyo, usually translated as "apply mutatis mutandis," is a drafting technique that makes one provision apply to another situation with necessary changes. It appears throughout Japanese statutes, including the Companies Act, Administrative Procedure Act, and many procedural statutes. Readers consult it when a provision seems to point away from the article being read. This article explains the reading method and does not decide how a mutatis mutandis clause applies to a particular case.
What Junyo Does
Junyo incorporates another provision instead of rewriting the same rule in full. The incorporated provision applies with changes needed to fit the new context.
In English, official translations often use "apply mutatis mutandis." The Latin phrase signals that words in the incorporated provision may need to be changed. For example, a rule written for a "requester" may be applied to an "applicant," or a rule written for one procedure may be applied to another procedure with adjusted terms.
This does not mean the incorporated provision is copied mechanically. The reader must identify the original provision, the new context, and any explicit replacements. Some statutes state the replacements directly, using phrases equivalent to "in this case, the term X in Article Y is deemed to be replaced with Z." Other statutes simply say that a provision applies mutatis mutandis, leaving the necessary changes to be read from context.
For article writing, do not summarize only the article containing the mutatis mutandis clause. Explain what provision is being incorporated and what procedural effect follows.
Find the Source Provision First
The first step is to open the provision being applied mutatis mutandis. The clause cannot be understood in isolation.
If Article 20 says that Article 13(3) applies mutatis mutandis, read Article 13(3) first. Identify its subject, condition, notice requirement, deadline, or legal effect. Then return to Article 20 and identify the new situation to which that rule is being applied. Only after both provisions are visible can the reader translate the clause accurately.
This matters because the source provision may contain its own exceptions, provisos, paragraph references, and item lists. A mutatis mutandis clause may bring those details with it unless the statute excludes or changes them. If the source provision contains a deadline or notice requirement, that deadline or notice requirement may become important in the new context.
When the source provision is long, avoid a bare sentence such as "Article X applies Article Y mutatis mutandis." Add one substantive sentence: "This means the same notice interval used for third-party opposing opinions also applies to the review decision described in Article X." That gives the reader the operative effect without reproducing the whole source article.
Watch for Technical Replacements
Japanese statutes often include technical replacements after a mutatis mutandis clause. These replacements are part of the rule and should not be skipped.
A replacement clause may say that "the term A in Article Y is deemed to be replaced with B." It may replace a person, organ, document name, deadline trigger, procedure name, or statutory reference. Sometimes a provision applies mutatis mutandis to several articles, and the replacement sentence covers multiple terms across those articles.
If there is a replacement table or long replacement sentence, read it before paraphrasing. A small replacement may change who must give notice, who receives the document, or which decision starts the deadline. In procedural statutes, those details often determine the practical effect of the rule.
Do not translate replacement language loosely if it affects the operative rule. It is usually better to state the effect in plain English after naming the source article: "Article X applies Article Y with the decision-maker changed from the head of the Administrative Organ to the Incorporated Administrative Agency."
Junyo Is Different from Direct Application
Junyo should be distinguished from direct application, delegation, and reference. The words may look similar in English summaries, but they do different drafting work.
Direct application means the provision applies as written to the case. Mutatis mutandis application means the provision applies with necessary changes. Delegation means another rulemaker may prescribe details by Cabinet Order, Ministerial Ordinance, or another instrument. A reference may simply point the reader to another provision without incorporating it.
This distinction matters for legal explanation. If a statute says that Article 13 applies mutatis mutandis, an article should not say that the new case is "the same as Article 13" without qualification. It is the Article 13 rule adjusted to the new context. Conversely, if a statute merely refers to another article for a definition, the referenced article may not import all of its procedures.
When writing in English, "apply mutatis mutandis" is accurate but not always reader-friendly. Use the phrase once for precision, then explain the effect. For example: "Article 20 applies the Article 14 third-party notice rule mutatis mutandis, so the same interval before disclosure applies to the review outcome described there."
How to Cite Junyo in Articles
A good citation identifies both the applying provision and the source provision. This prevents the reader from losing the chain.
Write "Article X applies Article Y mutatis mutandis" when the article's main function is incorporation. If the source provision affects a right, duty, deadline, review route, disclosure decision, or official duty, add a substantive explanation of Article Y's effect in the Article X context. Do not leave the reader with only the Latin phrase.
If the mutatis mutandis clause contains replacements, include the important replacement in the explanation. If the replacements are too numerous, state the main one and avoid over-summarizing the rest unless the article is specifically about that procedure.
If a mutatis mutandis clause is minor and the source provision is explained elsewhere in the same article, a short reference is acceptable. But if the source provision is the only reason a reader has a procedural right or deadline, explain it in the section where it appears.