A friend of the mother, Sumire, visits their home. Her pure beauty captivates her son, Sho-suke. Due to nervousness, he can't speak properly and ends up exchanging a passionate kiss after taking a joke seriously. Late at night, Sumire is aroused by the young man's kiss and cannot sleep due to excitement. Just then, Sho-suke arrives… They tell each other that this will be only for tonight as they entwine their bodies. However, the young man's sexual desire does not subside so easily, and the next day, Sho-suke sneaks into her room again...
