What is with the shift in Total Eclipse after episode 2? I started watching Total Eclipse, which I understand is part of Muv-Luv, but I am unfamiliar with. After episode 2, it seems like the whole tone of the show shifts. Is there some background into what's going on? The first two episodes reminded me a bit of Blue Gender, but after reaching episode 9 it seems like that was totally left behind.
I have not played the visual novels and have not seen any other MuvLuv content, so I can only judge from the anime series. In this series, the two first episodes focus on the background of Yui. You basically witness what she has experienced when she was younger, and then the shift focuses on the 'current day' situation, where Yui is one of the two lead protagonists. Further down the series she reveals some of her background which is consistent with the first two episodes.