Seriously, why this pairing? Even the school mode ending has barely any romance to it. I'm honestly curious. Or are you just shipping for the sake of shipping?

She is the character that some people like. He is the protagonist.
The rest is simple. That was the whole point of the school mode I think. "What if?" scenario.

And, after all, this game is not about romance (the main game that is, not the school mode), so there are about 1,5 characters that could be considered any sort of real pairing with the protagonist.