Under the system of centralized administration established with the ritsuryo legal codes, the Joko was considered as having authority equivalent to that of the Emperor, so even such an irregular form of government was possible within the framework of the system.
日本の律令下では上皇は天皇と同等の権限を持つとされていたため、こうしたやや変則的な政体ですら制度の枠内で可能であった。