Takashi Horimachi is an ordinary curious fifth grader attending "Anytown" Elementary School. One day, a very unusual transfer student named Tarou Tanaka joins Takashi's class. Takashi and his classmates have never encountered anyone quite like Taro before. He is blue, has huge glowing eyes, pointy ears, a smooth bald head and one horn. Takashi, obsessed with trying to figure out this strange new visitor, attempts to track Tarou's every move; and in the process he continuously falls victim to Tarou's hilarious assortment of cosmic jokes and traps.