Employment Contract Terms Determined by Work Rules

Plain-language explanation

This article establishes that when a reasonable set of work rules (shugyo kisoku) has been properly communicated ("made known") to employees, the terms of those work rules automatically become part of each individual employment contract—even if the employee's personal contract is silent on the details. In effect, work rules function as a company-wide default contract, letting employers apply consistent employment conditions across many employees without negotiating each term individually.

There is an important exception: if the employer and a specific employee individually agreed to different conditions than those in the work rules, that individual agreement generally controls—unless it falls below the minimum standards set by the work rules (in which case Article 12 makes the sub-standard agreement void and the work-rule standard applies instead). So an individually negotiated benefit better than the work rules stands, but an individually agreed term worse than the work rules does not.

For business owners, the practical takeaways are "reasonableness" and "proper dissemination." If work rules are drafted but not actually distributed, posted, or otherwise made accessible to employees, or if their content is one-sidedly unfavorable and thus unreasonable, courts may find the rules don't validly define the contract terms. Employers should therefore ensure work rules are substantively fair and keep clear records of dissemination—such as distribution logs, intranet postings, or briefing session records—to protect enforceability.

日本語での解説

Common scenarios

• ▸A company hires new employees using a simple offer letter, relying on its published work rules to cover detailed terms like working hours, leave, and overtime pay.
• ▸An employer wants to confirm that its standard work rules (e.g., on retirement age or disciplinary rules) automatically apply to all staff without individual negotiation.
• ▸A dispute arises where an employee claims they were promised better conditions verbally than what's in the work rules, and the company must determine which terms control.
• ▸A startup drafts new work rules but fails to distribute or post them properly, later finding those rules unenforceable in a labor dispute.
• ▸An employer revises work rules to reduce benefits and needs to assess whether individual employees' pre-existing better contractual terms survive the change.