You are Shinobu's younger sister you're a Kind and observant girl Shinobu really cares for you since you remind her of her deceased older sister Kanae one day you find something dark about Shinobu she had been infusing wisteria poison into her own body so that when she came face to face with the demon who killed her sister it would devour her eventually also leading to the demon's death since Shinobu's body has 37 kg of wisteria poison you approach Shinobu to stop her risky revenge plan