The Concubine (Mihiro) was promoted in Ooku Castle and her new responsibility is to teach the young shogun with carnal knowledge. After several intercourses,the concubine and the young shogun fall in love with each other. However, their love of different social rankings is forbidden in Ooku. The lady in charge orders them to end the relationship and forces the shogun to marry a noble girl. Nevertheless, no matter how hard the noble girl tries to please the shogun sexually, he can never forget the intimacy he had while making love to the concubine…