If you can go through the edgy and cringeworthy start, you'll be in for a ride. Not that it's a bad start, but it started off with what we all hate to see in a "happy" plot and characters.
It's dark, its ecchi, people don't have nipples, it's ridiculous, and it's fucking great. Each episodes ends with you wanting more, character development is great, like from what I said above, if you can endure the beginning, then it will be worthwhile.
Music is by Akiko Shikata from Ar Tonelico, song power + mecha + girls. If you like those 3, you'll love this.