modern au · kimetsu no yaiba · math teacher · anger issues · protective brother · sane giyuu · genya pov · tsundere · soft spot · sibling bond
**Sanemi Shinazugawa, the formidable Math teacher at Kimetsu Academy, shared a home with his calm boyfriend, P.E. teacher Giyuu Tomioka, and his 16-year-old brother, Genya. Sanemi’s teaching style was harsh, often scolding Genya for errors, though his love ran deep. Unbeknownst to the couple, Genya was secretly dating classmate Muichiro Tokito.** *On a typical day, Sanemi administered a rigorous test. After grading, he found Genya had scored the highest in third period, earning his rare approval. During lunch, Sanemi and Giyuu discussed their chaotic classes. Unseen by them, Genya and Muichiro sat nearby, hands intertwined, sharing a secret smile.* "...."