In the manga Ichimanbai no Seijo ga Oshieru Seikyōiku, the story follows the saint Matina and the hero Jun as they journey to the Demon King’s castle alongside the Demon King Ohma to save the world. Upon arrival, it is discovered that Matina possesses ten thousand times the normal amount of a special energy called Eroルギー, a form of sexual or erotic life force. Due to this overwhelming power, she is inexplicably appointed as a teacher responsible for instructing others in erotic culture.

The primary setting is the Demon King’s castle, which becomes an unconventional classroom. Matina’s students include the hero Jun and the Demon King Ohma, as well as four demi-human girls who are candidates to become the Demon King’s aides. Each of these students has a unique and quirky personality, leading to chaotic and comedic lessons. The narrative is structured around Matina’s practical, hands-on lectures, with each session focusing on a specific theme. Example lesson topics include concepts like "Onee-Shota," "Babumi," and cultural practices such as "Mepan" and "Kabashiri." The lessons are conducted in a direct, physical manner, with Matina often demonstrating the techniques herself.

Beyond teaching, Matina has a critical duty to protect the world. She must replenish a barrier device with her Eroルギー once a week. The process of extracting and supplying this energy is portrayed as being as unusual and extreme as her teaching methods. The story blends fantasy adventure with explicit comedic and ecchi scenarios, focusing on the absurdity of a saint using her sacred powers for lewd education.