Based on a series of novel. Boy is son of prime minister of independent world when empire of genetically engineered humans called Abh role into town. Prime Minister makes a deal for the surrender of the planet that makes him, and thus his son, nobles in Abh Empire, much to the dislike of much of the populace.
Boy is sent to join Abh Star Forces uears later (as a supply officer) as service is mandatory for nobles, meets young Abh royal.
Then there's small matter that there's another large space empire who rather dislikes generically engineer types, and a war breaks out (Crest is pre-war, the Banners are during).
Some of the largest fleet battles of any visual SF are involved.
It has a very deliberate pacing- it feels a bit slow at times, but it also wastes no time on recaps or rehashing of stuff you know and no filler whatsoever. A lot of time is spent on the exploration of Abh culture. The Abh as a whole aren't exactly the good guys, just the side that the main characters happen to be on (on the large scale it's sort of grey-grey. The UM is a bit worse than the Abh, but you can see where they're coming from, and both of the major powers are imperalistic with what that entails, just in very different ways). There's also a lot of character development of the leads.
Melancholy of Haruhi, at least the first season (the second season has Endless Eight, which reduces the dollar efficiency of the purchase).
It's a slice-of-life school anime with lots of character development, and the title character is something of a reality-warper but doesn't know it, who is obsessed with aliens, espers, and time travelers but doesn't think they exist, is in a club with an alien, esper, and time traveler who are trying to keep her out of the loop of such things, and the main viewpoint character is a deadpan snarker.