Source order
- Japanese government, operator, airport, railway, or merchant source.
- English version of the same official source, checked for omissions.
- Independent evidence when an official source cannot answer the practical question.
Evidence labels
Each decision guide states its official-source check date and whether any product, route, or process was personally tested. Desk research is never presented as firsthand experience.
Commercial independence
Affiliate availability does not decide the conclusion. Every commercial guide identifies who an option suits, who should skip it, and at least one reasonable non-affiliate alternative.
Use of AI
AI may assist with research organization, comparison structure, and draft editing. It does not create personal experiences. Claims are checked against cited sources before publication.