Rape Panic Mansion (1996)

Keiko, a lonely single woman living in Tokyo, is taking the elevator up to her apartment one day when a couple of young thugs suddenly appear. They immediately assault her, dragging her into a stairwell and taking photographs of her in the throes of her ordeal. She leads them to an apartment inhabited by Miho, a woman she often sees in the building. The men burst in and, after repeatedly beating Miho’s partner, subject both women to endless rape and degradation. In the midst of their mutual torment, the hatred that Keiko and Miho share for each other explodes, revealing them both to be as ruthless as their captors.