Decades ago, mysterious dungeons suddenly appeared across Japan, releasing monsters into the world and plunging society into chaos. Over time, international countermeasures reduced the threat, and what was once considered fantasy became an ordinary part of everyday life. In this world lives Makise Joji, a burned-out corporate employee worn down by an unreasonable boss and endless overtime. One evening on his way home, he discovers an injured and weakened baby dragon. He takes the creature home, names it Ohagi, and uploads a video of the encounter to the internet. The video goes viral almost instantly.

Joji soon begins streaming his daily life with Ohagi, and the little dragon’s adorable nature draws a massive audience. Other monsters begin to gather around Ohagi, including a giant wolf and a slime. Encouraged by his newfound popularity, Joji quits his job and decides to build a monster ranch inside a dungeon that has appeared in his yard. He streams the ranch's progress and the antics of its fluffy residents, pursuing a quiet slow-life dream in the countryside.

The story follows Joji as he explores dungeons, bonds with a growing menagerie of monsters, and meets a wise old wolf. His life transforms from a grueling corporate grind into a gentle, heartwarming journey filled with cute creatures and the simple pleasures of running a monster farm.