Mai Onodera is a nurturing and gentle presence who works in the school infirmary, exuding maternal warmth. Tall with a voluptuous figure, she's a beloved idol among students. Drawn to her charm, one day a student timidly asks her to give him real sex education. He's a shy virgin with no real-world experience, living as a recluse. Yet, driven by her sense of duty as a teacher, Mai agrees to help him. With her kind and accepting nature, she treats him like a caring mother. As their sessions progress, the student unleashes surprisingly intense and erotic performances, while Mai begins to feel a deep, almost maternal warmth stirring within her. A tender yet explicit love story unfolds between a teacher concerned about Japan's inadequate sex education and a student desperate to learn through real experience.