Nanami has been married to her husband for five years. Though their life was ordinary, she had been happily supported by her husband's kindness. However, she betrayed him, secretly building an intimate relationship with Takashi, her husband's son from a previous marriage. Day after day, hiding the truth from her husband, Nanami indulged in a taboo affair with her stepson. That night, once again, she quietly moaned, suppressing her guilt as she enjoyed passionate sex with Takashi.