Aside from his incredible reactions and facial reactions, Uenoyama is indeed someone to look up to. It's not easy to be with someone who's currenly - and literally - moving on from a past, but he's enduring. I feel like crying a lot once Uenoyama's heart becomes broken. But remember his answer to Yayoi when she asked him about his feelings for Mafuyu? I guess he knows that he'd be hurt. And he's ready.
This plot revolving so much around Yuki would be the main heartbreak between Uenoyama and Mafuyu for sure. It'll hurt a lot, definitely, but let's see who will sensei handle the built drama.
*how will sensei
Hahahaha typos (=・ω・=)