A secret sex movie of Kana Momonogi with her sister’s lover, Kana Kimiiro. One day, her sister brought her boyfriend home and accidentally opened the bathroom while she was bathing. With her sexy body and big breasts, who wouldn’t fall in love with her? But before the guy could flirt, his younger sister asked him to fuck her first. Unexpectedly, her lustful instincts arose and she stole her sister’s boyfriend. When her sister found out, she begged her to let her lover go, but it was too late….