Usually, I'm rooting for Maria or just full on harem, but I think I might end up favoring Sophia this round. Poor girl has probably been miserable for a whole decade by now, and despite the time change Katarina not only has a novel buddy, but also finds her genuinely attractive. Also, it'd be interesting to see how her relationship develops given that Katarina only had her memories appear briefly and much later on, much like Sophia only getting vague vibes for a long period of time.
All I'm saying is, I'm happy Sophia's content with friendship in the main story generally, but I'd love to see if she changes and goes for gold here.