True beauty, who teaches math at a school in Tokyo marked with ●, is popular among students due to her cheerful personality and easy-to-understand lessons. On the other hand, she has been stuck in a completely sexless marriage with her husband for over a decade, leading to days filled with frustration. She harbors a secret that she can't tell anyone. It's this... She skillfully guides her students, who have an abnormal admiration and idealization of 'older women,' into secret physical relationships, using sex with young men to vent her daily frustrations.
