Yuki is a beautiful and composed older woman teacher. During class, she strictly and carefully guides her students, but privately harbors a slightly naughty side. One day, she's lured into a room under the pretext of practicing sex, leading to an intimate encounter. As they begin grinding, her arousal naturally builds. Suddenly, Yuki cries out, "Ah! It went in!" Once her hips start moving, they won't stop, and overwhelmed by pleasure, she loses consciousness as creampie occurs. What started as mere practice quickly turns into real sex before she realizes it.