This chapter critically examines the development of the Japanese adult guardianship system. It identifies the inadequacies of the previous system and points out the distinctive features of the new system, principally the addition of advisorship and the incorporation of the continuing power of attorney system. It is argued that the Japanese system does not comply with the demands of the greying society: the appointment of guardians accounts for an overwhelming share of cases, the use of continuing power of attorney is virtually stagnant and the system centres on asset management, with inadequate functions for support in daily life and ability to help oneself. In light of international developments in this field, it encourages the adaptation of a human rights perspective rather than the traditional healthcare policy perspective and further proposes that a combination of trust and adult guardianship system would be beneficial to society; the assets of the person concerned could be managed by the trust system and the livelihoods of the persons could be managed by the continuing power of attorney system, which better respects self-determination.