For Uncle, a lecherous but handsome toilet designer, it is just an ordinary day of neglecting his duties as a single parent to hit on women and talk about his "superpower": his ability to tell a lady's hip size at a glance. But when he is sucked down into a toilet, the Space Peace Republic Alliance Hero Committee gives him real superpowers, and he becomes the hero of Earth. There is only one problem—he has become an ugly, unrecognizable fatty who is unable to reveal his real identity.

Uncle's beloved daughter Min-chan does not believe that such a vulgar fatty could be her father, and casts him out of his own home. Distraught and homeless, he joins up with his perverted neighbor Yamada-san, a small man with a fondness for streaking, and sets out to convince Min-chan that he is her father.

Full of sexual innuendo and slapstick humor, To Be Hero follows Uncle as he befriends bizarre allies and combats even more bizarre foes, fighting for the future of earth against aliens and—more importantly—his future with his daughter.