An operative of the Supernatural Phenomenon Treatment Bureau along with Ouka, she works as a monster slayer. She gained the title of Grim Reaper after slaying 1000 monsters; wearing a skull mask as proof. She seems to have feelings for Ouka with their similar quality towards their inability to love someone, getting into a fight and nearly killing Kyōka. She first met Ouka after she was brought to the Supernatural Phenomenon Treatment Bureau when a supernatural phenomenon wiped out her village, leaving her as the only survivor. She nearly killed Ouka without mercy if it wasn't for his fast reflexes but soon joined up with a pink haired Grim Reaper (Grim Reaper II). She fights with a katana and talks cheerfully, especially when it's about slaying monsters.