Kazuya can't control his joy when he hears that his mother's friend, Umi, who taught me how to study when he was a student, will return home for the first time in a while. The reunited Umi is more beautiful than before ... Kazuya, who still seeks her secret feelings for her, has a relationship with her too much. Kazuya, who has lost her control, continues to be swept away by her lust and seeks her crazy. However, she says that such an extraordinary relationship cannot continue.