Maeshiri is an ordinary office worker with a very unusual trait: his butt is on his front. He lives a secret double life as the hero Oshiri-Front Man. When a strange drug that moves people's butts to the front spreads, he investigates a pharmaceutical company and uncovers the "Oshiri-Front Empire Revival Plan." To stop a vengeful villain from resurrecting the ancient empire, he must seek training from his former mentor.