Kasumi, now a coach for the competitive swim team, was popular among her students and enjoyed her daily coaching routine. But one day, while training alone at the pool, she secretly used a waterproof vibrator underwater for pleasure—only to be accidentally spotted by a fellow teacher. The incident was soon witnessed by students, and she became labeled as the "lustful teacher" throughout the school. Forcing her into a tight competitive swimsuit, the students subjected her to humiliating acts inside the sacred classroom...