In a cramped room of the Spider Mansion, Miki wears a gag as usual, pleasuring herself while tightly binding her own body. This restrictive state is her only comfort, and once again she indulges in masturbation, layering multiple gags upon herself. However, today she forgets to lock the door, and is suddenly discovered by someone who barges in unannounced. This incident will bring a dramatic change to her everyday life.