A ten-year-old insect named Oshiri Kajiri Mushi XVIII attends Biting School, where he is training to take over his family's Biting Shop. More than anything, he loves to sing and dance cheerfully. A bite from a Bottom Biting Bug transforms people: slouchers stand up straight, gloomy folks break into laughter, and the timid suddenly feel sure of themselves. Still, even he gets plenty of things wrong. This fourth season of the short gag comedy runs ten episodes, drawing on ordinary daily situations and the kind of silly humor children enjoy.