In this manga adaptation of the popular web novel series, an overworked wage slave finds himself transported to a fantasy world where he quickly becomes the strongest sage in the world... thanks to the help of an army of tamed Slimes! 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. While on a reconnaissance mission inside a creepy laboratory hidden in the middle of the wraith infested forest, Yuji's Slimes are spotted by the facility's security system. With the poor Slimes caught in the cross-hairs of the bloodthirsty system, programmed to protect the organization at any cost, will Ancient Rhino and Yuji make it in time to save them?!