Yui, a busty girl who grew up in Tokyo and was cherished by her parents, had returned to her paternal grandparents' home for a visit to pay respects at the grave. One day, while her father went to a friend's house, leaving Yui behind, she saw her uncle sleeping on the veranda and noticed that his crotch was erect, just a physiological phenomenon. Unaware of sexual knowledge, Yui found it strange and, out of curiosity, touched his crotch and, out of mischief, stimulated him until he ejaculated. From then on, 'Yui is a naughty girl' spread among her uncles, and she became a target...
