The protagonist, Old Man, is very attractive but a terrible slob, a failure as a father, and works as a toilet seat designer. He is divorced from his wife, and lives with his daughter, Min-chan, who is both very smart and athletic. One day, as he was taking a dump, he was sucked into his toilet and given the important job of becoming a hero to save the world. He ends up having to give up his good looks for a chubby frame in exchange. Old Man's battle to protect the Earth and Min-chan is about to start.