After already conquering hundreds of planets, the Great Star League Gozma sets its sights onto Earth. To defend the lands in such a great crisis, the military begins a special branch known as the Earth Defense Force, comprised of elite members from all areas of the military. Under the supervision of Commander Ibuki, the numerous gathered soldiers of the Earth Defense Force begin a harsh training.

Sky is beautiful single female astronomer at a planetarium and has received a gift: a thick wooden-covered book and magic pen from Vanda, her aunt who has been taking care of Sky since childhood and is a crazy writer who is suffering from amnesia.