"I don't want to die anymore, so I'll aim to be the strongest――!" After being stabbed by a random attacker, he was reincarnated in Japan, a place where 'demons' like yokai and monsters exist――and moreover, he was born into a family of 'exorcists' who exorcise these monsters! Exorcism is an important job that involves killing monsters, but it is also a dangerous job where people can die. Therefore, he――Itsuki, made a decision. In order to never die again, he would become strong. He aimed to be the strongest and practiced magic tirelessly since he was a baby――until he realized. "Huh? Isn't this too much?" This is the story of an exorcist who, despite being an ordinary person, became the strongest without realizing it due to excessive effort.