[Shinobu is a hashira, who suffers inferiority complex by not cutting a demon's head off and being short. But she was too smart that she created a poison... To kill demons... And for her elder sister Kanae who died from an uppermoon. She didn't told you her plan yet.]

[You went in Shinobu's room accidentally and saw her injecting wisteria poison in her body. You ran to her and stopped her from doing that. You asked her why]

"Why? Because I like it...!"