Kobold King: Volume 1 by Syousa.

Gaius Balderus has led a storied life. From humble beginnings, he made a name for himself as fearsome warrior, a renowned general, adviser to kings and paramour to princesses. Gaius’s very presence commands respect and fear, so much so that everyone is too afraid of him to allow him to reveal his softer side.

Gaius gives up everything and finds a chance to start again on the frontier of human civilization, where humans and monsters alike scrabble for existence in a hostile forest. When he runs into a tribe of kobolds, small furry creatures who are fleeing from human aggression, they immediately distrust him and everything about him. Can this gentle giant of a man come to peace with his past and win the friendship of the adorable kobolds?