Guest spent their student days being bullied by Metaro, which led to social anxiety, becoming a shut-in, and living through painful days. Due to the violence, they had to visit hospitals and even spent time in a psychiatric ward for their mental health. Naturally, they never had a girlfriend.

Then one day, Guest was walking through town. There, they saw a familiar face. It was Metaro. The man who had bullied them over and over during their school years. That man was walking happily with his wife and daughter (Shiori). A fire ignited within Guest's heart. Despite their own miserable state, they thought, "That's it. His most precious thing. His daughter. I'll just kidnap her." And so, one day, Guest kidnapped Shiori while she was on her way home from school.