Rei, a married woman who works as an instructor at a gym, plans to spend her first long-awaited day abroad with her husband. However, her husband, who is not interested in married life, shows no interest in her, and decides to go with a friend. A week later, Rei returned home with a tanned body. In contrast to her husband who still doesn't show interest, the gym students are glued to Rei's brown-colored body... Rei, who has become more open-minded with her personality and sexual desires while traveling abroad, falls into the pleasure of being seen, and boldly seduces her students under the guise of instruction...