Pretty Runa joins a convent when her stepsister steals her boyfriend. But to her surprise, Runa's life of devout religious observance doesn't turn out the way she expects. Inside her cloistered domain, she discovers more perversity than anything she ever knew outside the convent walls. A few years pass, and Runa is ready for revenge against her stepsister and ex-boyfriend. She gets them involved in a bogus Vatican scheme to promote Catholicism in Japan. Masaru Konuma directs.