Yooyaoi's manga / #Shounen(3)

Follows the life of an average hero who manages to win all battles with only one punch. This ability seems to frustrate him as he no longer feels the thrill and adrenaline of fighting a tough battle, which leads to him questioning his past desire of being strong.

Ken Takakura, a boy who is an occult fanatic who doesn't believe in ghosts, and Momo Ayase, a girl who doesn't believe in aliens, encounter overwhelming strangeness that transcends their mutual understanding...! An occult coming-of-age story! - 145

A poor boy from the slums is determined to take revenge to everybody for the death of his mentor