Truthfully I think that bomb that everyone is talking about because Suzuka is being nice is going to be that Arima made a pass at her in America. I think if Yamato where to hear this news it'd piss him off. First because Suzuka was in America for a year with him he'd be doubting if anything did happen because he doesn't have any back-up sources besides Suzuka's words and Arima's. He's not really on speaking terms with Arima so that's out of the question. When they weren't even going out he was very jealous of someone he thought was seeing suzuka enough to follow her home. Then after he learns about the dead guy, he gets mad that she won't get over him. Mind you to the people who don't know it's a while after he learns of the fact. Then the way they left eachother too. He still liked her, I'm betting she still liked him. It just doesn't seem feasible that the person who he's talking about marriage to is Suzuka. Hell this niceness that Suzuka is experiencing right now could be because she was gone from Japan for a year, something about a change in personality. She could've thought, hey I need to stop acting like I was to Yamato or he really is going to leave me (assuming she still liked/likes him). Or just an overall change because being in a foreign country like that could do it to you.