Kenji Ezure

Mr. Kuni is here. Again. And he does the usual. When Megumi, the sister of our heroine whose name I didn't catch, is found dead she joins a band of teen whores lead by Aya and together they begin punishing all of the men who have sex with girls, in hope they'll eventually find Megumi's killer and have their revenge.

AKA Escape Captivity: The Movie; A girl named Kimika (Sakurano) wakes up chained up in a dark boiler room, unsure of how she got there. She's soon approached by a strange large man wearing a mask and using a creepy voice changer. (imdb)

Mina and Mizuki sisters attended a ballet class in Tokyo. One day, the sisters return home separately, but the younger sister, Mizuki, is kidnapped on the way home and discovered as a corpse. On that day, Mina blames herself for returning home and leaving her sister to practice ballet staying. Her mother, Teruko, is also very upset by the news of the discovery of her body, causing deep emotional wounds.