Yamisaka Ouma (闇咲 逢魔 Yamisaka Ōma?) is a Japanese magician introduced in Toaru Majutsu no Index in Volume 5. He is adept in the use of a magical azusayumi crossbow, which amplifies the power of his magic. He appears to capture Index in order to access a grimoire inside her that would allow him to save a woman who has been cursed to die.