The protagonist, known only as "Ossan" (pops), is a handsome yet undisciplined man, a divorced father who has a job as a toilet seat designer. He lives with his daughter Min-chan, who excels in both academics and sports. One day, while on the toilet, Ossan is sucked into it and becomes a hero charged with protecting the world. In exchange, he transforms from his handsome form into a chubby appearance. Ossan's fight to save the world and protect Min-chan begins here.