Mai, a mother, is troubled by her son Aisei Isshiki's unusual anal fetish and decides to personally use her body to provide him with sexual education in an attempt to correct his behavior. However, her son's demands gradually escalate, leaving Mai increasingly confused. With no justification other than "for his education," she finds herself compelled to comply with his desires, torn between her duties as a mother and her own growing pleasure. The story deeply explores the shifting dynamics of their relationship and the complex emotional transformation Mai undergoes as boundaries blur.