Aiko, a female college student, lives in a mysterious apartment complex called Maison de Yukimura. Yukimura, the building's manager, routinely checks her room every night for the presence of a suspicious unknown man. Under the name Kontan, he continues his surveillance, claiming it is to protect Aiko. However, this watchful eye gradually uncovers the real dangers threatening her. The delicate touch of ropes begins to dominate her body, awakening her from a daze. Here unfolds a secret tale where training and bondage intertwine. Amid an eerie and seductive atmosphere, Aiko's appearance slowly transforms. Confined within the walls of the apartment, her life takes a sudden, unexpected turn.