During a sweltering summer, Sayuri is practicing her serves at the gymnasium. She's been staying late every day, training hard with her coach, Ueda, for an upcoming mothers' volleyball tournament. Though she appears plain and modest, Sayuri is actually a G-cup, carnivorous-type woman who loves both food and men—an irresistible married woman. One day, Ueda confides in her about being bullied in the past by a tall woman. Despite it being a trauma, Sayuri doesn't miss the movement in his crotch. The next day, she calls him out, taunting his face and stepping on it, whispering, "You really wanted this, didn't you?" Instantly, Ueda's crotch swells again...