Little Fenrir and the Huge Dungeon

Yasuhiro Nakano was a salaryman at a black company who once aspired to become a Tame Seeker. One day, he receives an egg left behind by his great-grandfather and, following his last will and testament, visits the World Tree dungeon. There, he is saved from a monster attack by an SS-rank Fenrir that hatches from the egg! With "Fukumaro," a creature who can somehow understand his language, as his partner, he decides to start his journey as a seeker once again. "Together with my companions, I will definitely reach the deepest part of the World Tree!" Bonding with monsters and meeting new allies, he heads toward unknown floors! An exciting dungeon-crawling fantasy about a former salaryman and his incredibly cute and reliable tamed monsters!