One day, when Kasumi returned home from shopping, she found her son Hideo sitting alone, shoulders slumped. He had just been rejected by a girl—the reason being that Hideo had never even experienced a kiss before. Wanting to ease his pain, Kasumi lightly kissed him on a whim. But Hideo couldn't stop at just a kiss; he reached for her body, giving in to passionate urges. The warmth and purity of his feelings began to transform their relationship into something entirely new.