This study aims to examine the 2026 Reform of Japan’s adult guardianship system and evaluate it from the perspective of self-determination and Article 12 of the Convention on the Rights of Persons with Disabilities (CRPD).
This study analyzes the background to the 2026 Reform, outlines its principal features and assesses its implications through doctrinal analysis of the amended legislation, legislative materials and relevant CRPD standards.
The reform introduces the principle of necessity, places greater emphasis on the individual’s will and preferences and increases flexibility within the adult guardianship system. However, the continued reliance on powers of consent and rescission indicates that substitute decision-making remains a central feature of the Japanese system.
As the reform has not yet entered into force, the analysis is limited to the legislative framework. Future research will be required to evaluate how the new provisions are interpreted and implemented in practice.
The reform requires family courts, assistants and other professionals to place greater emphasis on the ascertainment of the individual’s will and preferences. The practical effectiveness of the reform will depend on how these actors implement the new statutory duties in practice.
The findings contribute to ongoing international debates concerning legal capacity, supported decision-making and the protection of vulnerable adults in aging societies.
To the best of the author’s knowledge, this study provides one of the first English-language analyses of Japan’s 2026 adult guardianship reform and contributes to comparative discussions on adult guardianship, self-determination and supported decision-making.
