It is the Second Wolrd War ... but not as we know it. Eva Braun is a scientist, and Taishi Takamoto has been given a briefcase by his father just before said father is murdered by an insane general. And there are aliens falling out of the sky, attacking humans on principle. There is also the Kishin Corps -- they're trying to fight to aliens, which means they're also fighting the Japanese Kanto Army (who are trying to negotiate with the aliens) and the Nazis. They're fighting the Nazis basically because the Corps' (with whom Taishi's dad was working) main anti-alien weapons are three giant robots (one flies, one is a submersible, one is just big and brutal), and Taishi's case holds the (alien-originated) power unit with which they can build a fourth (though the technology of strictly rotary generators, vacuum tubes and hand-cranking). Except that the Nazis want it to build their own robot and win the war with it.
Throw in Eva's twin sister, a wrecked house full of "cute" orphans (who have switchblades), robots being launched from railway trains and a giant aeroplane, and a German scientist called 'Albert', and a plot that goes from Japan to Peenemunde, and cram it all into 7 episodes ....
