Sister Street Fighter: Hanging by a Thread

Original title: 女必殺拳　危機一発

Directed by Kazuhiko Yamaguchi

Koryu heads to Yokohama in search of a woman named Birei, kidnapped by diamond smugglers who move their hot rocks by surgically implanting them into the nubile buttocks of Chinese prostitutes. Koryu's older sister, working as a jewelry designer, is secretly, if unhappily, involved with the gangsters.