I can't remember this anime movie/OVA from the late 90's?

I don't remember if it was aired with the Saturday Anime thing on SciFi, but I remember it being in late 1998. The movie involves five or more girls, mecha, an unstopable alien invasion, and a boy who grows super fast. They all end up dying at the end to stop the invasion. I can't remember much else, but I can't find anything fitting this description.