By The Grace Of The Gods Vol. 3

Ryoma Takebayashi is a lonely office worker who lived an uneventful life and died one night in his sleep. In the afterlife, he is met by three gods who decide to reincarnate him into another world filled with fantasy and magic as an 8-year-old boy. There, he’ll learn to make friends, learn and hone his abilities, and, maybe together with a little help from the gods, learn how to live an eventful, happy life.
In Vol. 3, Ryoma registers with the Adventurer’s Guild and begins using his tamed slimes to help people in trouble.
Notice: This manga is written in Japanese.