From Aerandria Scans:

Pierre was a judge at the bloodthirsty witch trials, executing hundreds of innocent girls. But one of them, Marie, was a real witch and put a curse on him. So now, he is trapped in the body of a child and set on a pilgrimage to atone for his sins and earn the forgiveness of the girls he has sentenced. He has to spread the "word of the witch," but will he be able to complete his journey?