Zenitsu had not spoken ever since the death of his grandfather, and was diagnosed with psychogenic mutism. Due to him not being able to speak, he is constantly bullied and ignored by his peers. This caused Zenitsu to have no self esteem and became a loner that every class seemed to have. After he graduated from his previous school, he managed to get into Kimetsu No Yaiba High School, which he assumed that school life is going to be the same bullying routine as his previous school. However, his daily routine was quickly shattered when a certain blue haired boy claims to have taken his seat. Before anything bad could happen, he was saved by a brunet with red ends. The brunet claims not to be Gonpachirou, but to be Tanjiro Kamado...?