Kokoro Shimizu, a high school sophomore, finally gets his hands on the long-awaited new VRMMO, Monster Evolve Online—better known as MEO. However, the partner he chooses turns out to be none other than the weakest monster: a slime! Kokoro enjoys a slow and carefree playstyle at his own pace in MEO. But hidden within the slime is an unexpected evolution... Even though he was just playing casually, before he knew it, he had become super famous!? A brand-new, laid-back rise-to-the-top story!