Millennium-spanning space opera for children. One of the more cross-pollinated works in Matsumoto Leiji's hideously ingrown SF setting (Yamato etc.), serving most directly as a prequel to Captain Harlock (1978).
Nazi optics win an angsting space captain's war against the idiot human imperium. Yeah, those Nazis really knew what they were doing.
The plot is nonsense on every level, from the physics (as always, Emeraldas pirates a wooden brig-sloop suspended by wires from a Zeppelin in space) to the politics (Earth is run by caricatures of petty fools), all the way through to the drama, which is made up almost entirely of bold posturing in absurd situations. It's cool only in an anti-intellectual way, ridden with childhood angst. The pacing and artistry are considerably better than what I've come to expect from Matsumoto.