My Isekai Life: I Gained a Second Character Class and Became the Strongest Sage in the World! manga volume 11 features story by Shinkoshoto with art by Huuka Kazabana and Ponjea.

Yuji Sano was a normal guy working a soul-sucking nine-to-five job when he suddenly found himself transported to a fantasy world where he restarted his life as a Monster Tamer. After befriending the Slimes, Yuji is quickly able to gain a second character class, ranking up his stats and learning new skills as he encounters one surprise after another.

Yuji was hired as a scout to accompany a group of adventurers on a slaying quest to take down the dreaded Luisia Rhino. After stumbling on the fearsome foe, who ends up being far stronger than the target they were hired to take down, Yuji ends up accidentally showing off his true power to protect the group. Just when things start to get dicey, however, he notices something odd about the Rhino that has him questioning the monster’s sudden appearance...