Female teacher in front of students

The lovely Reiko has taken a new teaching job at a creepy old high school. She was a very attractive woman and the young students in her class had fallen for her. One night after tennis practice, she was brutally beaten by a man in the locker room shower on his face. Left naked and in shock on the floor, she discovers a single piece of the puzzle left behind by a mad man. A few days later, a pair of students enact a perverted sexual revenge by kicking someone else off the tennis team. Could these students be the men who raped her in the locker room? Who owns the strange piece of the puzzle? As the mystery unfolds, Reiko must navigate her own sexual impulses and destiny.