Muso Tokugawa is a Buddhist priest who appears in the Gantz story during the Buddhist Temple Alien Mission. He is summoned to the Gantz room along with other recently deceased individuals and immediately attempts to convince the other participants that the room is not a game or a survival exercise, but a place of trial where the fate of each soul is determined before it proceeds to heaven or hell. His motivations are rooted in his religious beliefs; he sees the entire experience as a spiritual test rather than a literal battle against aliens.

In terms of personality, Tokugawa is earnest and forceful in his convictions, becoming visibly angry when Masaru Kato tries to explain the practical rules of the survival game. This frustration stems from his conviction that Kato's explanation is a profane misinterpretation of a sacred process. He is not depicted as a combatant or a skilled fighter; his role in the story is primarily that of a participant who brings a philosophical and religious perspective to the chaotic environment of the Gantz missions. His key relationship is with Kato, whom he confronts directly, and by extension with the other players who dismiss his warnings. He does not undergo significant character development, as his appearance is limited to this single mission, and he does not survive or acquire any special abilities beyond the standard Gantz equipment given to all participants. His notable contribution is the brief but intense ideological clash he introduces into the narrative, highlighting the different ways people interpret their forced participation in Gantz's deadly game.