Fafner (2004)

The youth of Tatsumiya Island believed that they had ordinary lives... until the advent of the Festum, extraterrestrial intelligent life forms intent on assimilating all humans. Abruptly, their once peaceful island transforms into a high-tech military fortress to counter-attack the hostile aliens. Their shock intensifies when they learn that only they can pilot the Fafner, a class of humanoid-type robots that represent the final and only weapon against the Festums and their divine powers.