Himari's mother remarries and she moves into her new father's mansion, but she feels uncomfortable there. One day, her mother goes on a business trip and is away for two days, so she decides to go and stay with her boyfriend. Her stepfather readily agrees, but she ends up missing him and returning home in the middle of the night. To relieve stress, she starts drinking with her stepfather, but suddenly becomes sleepy and loses consciousness. When she wakes up again, Himari finds her limbs tied to the bed...