Isekai Ryouchi Kaikaku: Tsuchi Mahou de Hajimeru Koukyou Jigyou

After losing his life saving a girl from a random assailant, Tsuchida Michio wakes up to find himself reincarnated in a new world. Starting a new life as Cain Saintrose, the son of an aristocrat, Michio undergoes a baptismal ceremony at the age of five to bestow upon him skills. He is granted several spells, including "earth magic," as well as infinite magical power. This is the story of a little boy who brings smiles to the faces of the people of his territory with his earth magic and infinite magical power.

(Source: Comic Zenon, translated)