Marin is a typical junior high school girl with a loving adoptive family. Her life takes a drastic change when a mysterious mirage is seen in the sky above the entire Earth. Killer androids called Monomakia descend to Earth from the formation in the sky, which is called Brigadoon (named after a town in the musical of the same name, that only appears on Earth at certain times) and begin to hunt down Marin. As she seeks to escape, she discovers a blue "ampoule" in a shrine; from the ampoule comes a protector, a sword-carrying, gun-slinging alien called Melan Blue. Together they must save the Earth and deal with family crises, school prejudice and the police, and come to an understanding of Marin's past and Melan's unexplained mission, as well as learn to trust each other.
well this anime is like maybe 10 years old now. it was made in around 2000 and i have to admit, i thoroughly enjoyed it. of course there are loopholes here and there but hey, it's an anime. surprisingly, not only does it have its funny moments, and believe me, there were tons, but it's also really touching and sad. very realistic in some areas. well the idea anyway. the ending was a little open ended i guess although there were hints that they were happy together although it wasn't shown, only said in text. i wish i could have seen it though but oh well. it has been quite some time since i last enjoyed an anime so much. too bad it's finished now, hope to watch more great animes soon. all the episodes are on youtube so enjoy!