Hagesawa Ko is a soon-to-be adventurer that was unwillingly reincarnated or well, swapped bodies with an 3-year-old that also was a reincarnation. Hagesawa was so powerful, life was practically a story where he had no rival. This caused Hagesawa to become depressed, but in a coincidence, his life was flipped upside-down. What could Hagesawa's new life have to offer?