I guess there are spoilers:
They didn't really tie up the relationship between Yuji and ... either of the girls. Shana confessed her love to Yuji, but Yuji didn't confess back. They held hands while they were walking to what they thought was their death. But then the next day they don't hold hands on the way to school, they don't kiss, nothing! Then they end with Shana arguing with Yoshida. It seems implied that Yuji loves Shana, but since they don't outright say it, it leaves that sliver of doubt in my mind. That's why I think it's open-ended.
All in all, I'm sad that it's finally over . I really love this series, and I can't wait for the movie.