Kitagawa Beniko is a 16 years-old girl who has a relationship with Seno Sora. These two with Sora's brother have been friends since they were 4. When she turns 16, Sora asks her is he could propose to her when they turn 18 and she said yes. However, one day Sora died while protecting Beniko. Then Sora's twin brother, Umi, comes and blaims Beniko for his brother's death. Beniko is tortured by Umi mentally and sexually.