AllMovie

This anime retells the story of the second World War, supposing what might have happened had aliens invaded in 1941. Both sides of the conflict put aside their differences in order to deal with this new threat, and in the middle of the fray is a teenager named Taishi. Entrusted by his father to care for a black brief case, he finds himself the protector of the controls of a massive, mechanized robot weapon which everyone, allies and enemies alike, want to get their hands on.