Miyuki receives a short skirt as a birthday present from her husband. Miyuki feels embarrassed despite her age, but her son Tomoya urges her to try it on, as it is a present from her husband who rarely gives her anything. However, Tomoya's son begins to feel naughty when he sees his mother in a miniskirt. He then becomes aroused by the sight of his mother's panties peeking out from under the skirt...