A fictional shinigami (reaper of souls) from the Beastars universe. He is the main character and tragic protagonist of a popular play, which ends with his demise. The soul of the woman Ellen (for unknown reasons) is coveted by demons and elemental spirits that greedily seek to take it for themselves. As a shishigumi, it is Adler's duty to ensure all lives are taken by a reaper and nothing else. While protecting her life from the various demons so that he can fulfill his duty and take her soul when her time comes, he falls in love with Ellen. After finally taking her life, he chooses to reap his own immortal soul out of grief and as a demonstration of his love. He is played by the characters Louis, Bill, Juno and even Legoshi at different times in Beastars.