Saiki Kusuo knew Kageyama, who was called mob, when he was in kindergarten.
And what Saiki couldn't bear the most at that time was that mob... He was really too weak.
So much so that I can't take care of myself in school and will be bullied by bad guys in school.
Mob's younger brother Ritsu, who is one year younger, cannot always take care of him because he is not in the same grade.
So, things became out of control after Qi Mu accidentally rescued the mob who was being bullied by bad guys.
After that, mob's mother learned about Qi Mu's identity as a superpower
And came to Saiki's house to ask for Saiki's help - to take care of Shigeo at school
Although Saiki was in a rebellious and self-centered period at the time, he still didn't want to get into trouble.
But after receiving the mob's mother's request and Kurumi's mother's gentle (threatening) gaze,
Qi Mu finally embarked on the road of no return to take care of mob, a student who is one month older than himself.
Purpose: strive to become a reliable person every day