Fuji is a plain accountant isolated within the office, making her a convenient target for casual advances and a diversion from workplace stress. Undressed, however, she reveals smooth skin and a slender body. Perhaps because sex has been absent so long, her sensitivity is exceptional: she squirts and climaxes repeatedly, making him imagine he has become an extraordinary lover. Deciding she is too valuable to remain merely a plain married sex friend, he resolves to reshape her into his ideal mistress.