It's about a superhero named Captain Boomerang throwing his boomerang at invading aliens who want to eat human sex energy for food, the aliens also happen to be genetically cloned humans or maybe not with amnesia that can be fixed via alien kissing.
It's hilarious how it could be so boring.
It's worst sin is having a ridiculously long gattai sequence with no real interesting mecha battles to back it up. It doesn't earn that gattai at all.
I really hope that the feud between UQ Holder and Fate's crew is actually over some stupidly petty grudge match between Fate and Eva. Like, the reason we don't see the various other non/demihumans and robots from Negima who should still be alive is because they're too mature to form secret clubs and squabble.