A young wife, Rei, who married her company boss and lives comfortably with her brother-in-law Mamoru. One day, while her husband is on a business trip, she learns of the existence of her basement from her Mamoru. Out of curiosity, she heads to her basement, but in fact, it was Mamoru's trap to make her his plaything. As soon as she entered, Rei was deprived of her physical freedom, and was told, "From today, her sister-in-law will live here." The miserable life that is done to the limit of being raped and humiliated begins.
