Good story, wasted on an mc like osuma though. You can replace him with literally any B-rank and they'd still be more useful and less whiny. He's like an Amuro and Sakura combined into the ultimate disliked character. He gets like 90% of the screen time too, then they hit you with flashbacks from literally one episode ago. Once you make it out of the invasion arc I think you should be good...
I like how they focused on introducing and keeping around a bunch of characters. I found that pretty neat that we get to know their backgrounds and what-not's to a perfect extent.