A couple of scientists remain on their dying planet of Eltria with their two daughters, Amitie and Kirie, in the hopes of discovering a means to resurrect the world. However, when Granz gets ill, it appears that their ambition of restoring the planet would be dashed. Kirie goes off with her childhood friend Iris, against her elder sister's desires, to seek assistance from a faraway parallel world. They arrive in Japan to find the key to their planet's rejuvenation. They encounter Nanoha, Fate, and Hayate there.