An, living an ordinary daily life, gradually begins to feel dissatisfaction toward her husband. Deep within her heart, an uncontrollable desire lies dormant—until it's stirred awake by the gentle yet intense affection of her brother-in-law, Eito. Drawn into his advances, she eventually surrenders her body to him. Afterward, she awakens to new pleasures and sensations she could never experience with her husband, discovering an entirely new side of herself.