Misa is a beautiful wife who has been married to her husband Koichi for three years. Misa is not satisfied by her nightly married life with her indifferent husband, and she secretly satisfy her lustful desires by herself... Her brother-in-law Koji, who is currently retaking college entrance exams to attend a prep school in Tokyo, has moved from the countryside to Tokyo and the three of them live together. One day, Misa peeks into Koji's room...