Asuramaru 「阿修羅丸, Ashūramaru, lit. "Perfect Asura"」: Asuramaru is a possession-type demon weapon of the Black Demon Series. It resides inside a black sword that Yūichirō uses. Whilst in use, the blade develops a thick green aura. Like Mahiru Hīragi, he can call upon Asuramaru to fully use its power to attack opponents.