Kido Senshi Gandamu Eiji

A colonized space had finally achieved peace, until a mysterious enemy, the UE, enters the scene and attacks colonies and other targets. Our main protagonist is from a destroyed colony, safely living on another. Before fleeing and surviving the attack however, he is entrusted with a data package which contains the one hope for humans to stand up against this powerful foe, plans for a gundam. Flit Asuno has spent most of his years on this peaceful colony studying science and realizing the plans, cultivating in the production of one. One which Flit ends up piloting himself when his new home is threatened.