After dying in an unexpected attack on the road, he was reborn in Japan, a land inhabited by "demons" such as yokai and monsters. To top it off, he was born into an exorcist family! Exorcists perform the vital work of eliminating monsters, but it's also a dangerous profession where people can lose their lives. So he, Itsuki Kazuki, made up his mind. To avoid dying a second time, he began practicing magic as a baby, working relentlessly at it, until one day he realized: “Huh? Isn't this a bit much?” This is the story of an ordinary person who worked a little too hard and ended up becoming the strongest exorcist around.