due to bullying issues, mariko was transferred to a distant school. at her new school, she became the advisor for the art club, which only had one member, kuroi. one day, she saw kuroi being bullied. despite mariko's scolding, the situation did not improve, and she felt helpless. kuroi told her, "i'm happy just knowing you're protecting me." feeling both pity and love, mariko crossed the line with kuroi in the clubroom after school.