The year is 1999. Amamori Hajime is just a normal, everyday elementary school student, trying to study and hanging out with his crazy pals. But then one day as his father is testing a piece of equipment he has been working on, something causes it to blow up, taking the house with it! Now orphaned, Hajime is taken in by his uncle, who is an astronomer. There at his uncle`s observatory, he meets a girl he`s seen before and developed somewhat of a crush on. He finds out her name is Yukino Yayoi, and her parents run a ramen shop in town. But even better than that, she`s his uncle`s assistant! What luck! But Yayoi isn`t exactly what she seems. There is a reason she helps out Amamori-san at the observatory. She is the Millennial Queen (Sen-Nen Joou), specially chosen by her home planet, LaMetal, to go to Earth and help prepare for the possible annihilation of the planet.