Fairy in a Cage (1977) on Netflix

During World War II, the tyrannical Judge Murayama uses his military power to imprison and torture innocent people. Suspected of helping an anti-government movement, the lovely Namiji Kikushima is captured, along with a local kabuki actor. Helpless and unable to escape, the two are subjected to a grueling series of tortures including rope bondage and physical assault. As the Judge and his evil assistant Kayo revel in their perverse fetishes, a new military recruit they have hired named Taoka may be the key to the prisoners' freedom. He loves Namiji and will do whatever he can to help her, even if it means betrayal to organize an escape.

—Anonymous