AD 1999, the Earth was in a critical situation; a planet Lar Metal was approaching to the Earth. Meanwhile, Yukino Yayoi was heard about Lar Metal from Dr. Amamori of Tokyo Observatory. She was a junior high school teacher, but she also worked for Dr. Amamori who appreciated her astronomical knowledge. Actually Yukino Yayoi was Queen Millennia who had come from Lar Metal 1000 years before, and she had been watching human beings since then.
Soon, numerous meteors fell on the Earth, and people were in panic. In this catastrophe, Hajime, who was a student of Yayoi, came to help Yayoi. Yayoi invited him into a big cave under the ground.
(Source: AnimeNfo)
— Description from AniList community (anilist.co).
