A young woman named Yumika is lured into the subway and murdered. Coincidentally (or was it by some supernatural force?) her arm is found near the home of her grandparents. Clutched in her hand is a note describing her killer's tattoo. So, Grandpa begins searching the city to find a man with a tattoo which matches. Meanwhile, Yumika's twin sister comes to visit Yumika's boyfriend and they begin a torrid romance.