I don’t wanna sound so pessimistic, but the fact that Kagami is spending three months with MikaYuu date, showing them having good and quality time together, screams to me that some tragedy is on its way. Might take some time since they are still going down the memory lane and uncover Shikama’s and MikaYuu’s past, but this is still a common device used in narrative before misfortune strikes. Not to mention things like this happened in ONS before. Yuu saying his reason to live is Mika, Mika dies again. Yuu gets Mika back, he is forced to choose between his friends and Mika.