A hero saves a world, gets screwed over by the people he saved, comes back as a depressed teenager, and then gets pulled back in anyway. The setup alone is the joke. It's not about becoming stronger or saving the world again, it's about a guy who already knows how this ends, already hates it, and has to do it all over while actually being funny about his own powerlessness. The second time around he's not a hero anymore. He's just exhausted, which is exactly when adventure stops being escapism and becomes comedy.

A man was once summoned to another world and saved it, becoming wildly popular there. Then he fell into a trap that forced him back to his original world, where he had to begin life all over again as a baby. Years later he is a somewhat gloomy high school student, until an unexpected turn summons him to that same world a second time. What follows is an adventure fantasy with a strong comedic streak, built around a former hero who gets a second run at a world he already knows.