Jun is a very intelligent little girl who spends her time making all kinds of inventions. It goes as far as creating two small robots, Kichinosuke and Yukinojo, who become her best friends. Because of her intelligence, Jun gets into college at a young age. There she meets and falls in love with a boy from her class called Zero. Zero is interested in motorbikes but not in school so he is skipping the courses. He is behind in school and thus is found much older than the other students and is therefor humilated. On the other hand is Jun too young to be in college, so they make fun of her too. Thanks to their common passion for mechanics, Zero sympathizes with Jun. This is the start of a series of adventures where little Jun will try to allure her charming prince.