Takashi Horimachi, a typical fifth-grade student at 'Anytown' Elementary School, encounters the peculiar transfer student Taro Tanaka. With his blue skin, large glowing eyes, pointy ears, bald head, and singular horn, Taro stands out among the students. Takashi becomes fixated on unraveling the mysteries surrounding Taro, leading to a series of mischievous pranks and cosmic tricks that leave Takashi in amusing predicaments.