Yakumo's mother.

Spoiler

She was kidnapped and held captive when she was young. She eventually managed to escape, but was raped by the man with red eyes who is now Yakumo's biological father. She tried to kill Yakumo when he was young because of his red eye as she thought because of that red eye Yakumo will kill people. Eventually Yakumo realized his mother truly loved him for his existence regardless of his red eye.