Lady Moonflower (1976)

Kizaki abducts Yuriko, subjecting her to a harrowing ordeal of abuse and torture, all while documenting the horrific events. He uses these images to extort her sister, Yumeji, a respected flower arrangement instructor. Faced with the threat of public humiliation for her family, Yumeji confronts Kizaki. However, he reveals that his real obsession lies with her, leading to a shocking turn of events as he inflicts the same cruel fate upon Yumeji, unraveling the dark depths of his desires and the lengths one will go to protect family honor.