A man dies and reincarnated in a world similar to ancient Japan, where yokai more often then not, treated and threatened humanity like insects. Hes reborn as a Kappa, but due to his past life and the morals that came with it, he's kicked from his family group. He saves a girl who was nearly killed by a Wani(youkai kind), he saves her, and she spreads a tale about the encounter, he finds a shrine has been built, as thanks for his good deed, and he feels stronger.

Kami(japanese gods) are effectively just yokai who are worshipped and prayed to, like a evolution system.

As he gets stronger and closer to a Kami, he becomes more human like, he also welcomes other youkai to his shrine, those in need, a Young Kitsune whose lost her mother, a group of Tsukumogami, even a tengu and crow youkai.

Plot point:- The kitsune girls mother became a Yurei(a ghost), particularly a Onryou, a Vengeful ghost(look up Hisuian Zorua lines, they are based on Onryou, especially behavior).
-Raiju attack, love at first punch, Kappamaru(thats the Protags name until chosen name) punches one of them, a girl, and shes now got a crush.