Ayumi, a wife who has not had sex with her husband for a long time, is a little dissatisfied. Recently, her only enjoyment is having tea and chatting with her brother-in-law, Shunsuke... However, Shunsuke lost money on gambling and is covered in debt, so he approaches her with the intention of belittling the frustrated Ayumi and taking her money. Then, just before their 10th wedding anniversary, while her husband is away, Ayumi is swept away by Shunsuke's forceful confession and is pushed down. Ayumi is tormented by a sense of guilt, but Shunsuke takes advantage of this and is not satisfied with just playing with her body...