The ending was just too unnatural, I didn't see any 'obvious' moment that jojo liking hyeyong, all that I can see was Jojo is forcing herself to like hyeyong because he like her too, it feels like jojo pitying hyeyong feelings for her so she wanted to try liking hyeyong, like make herself suffering.
Jojo should dating sun oh in the end instead, the chemistry between them still there in season2, but, I can see that the director/producer/writer or whoever make the storyline is forcing too hard to make jojo lose her feeling for sun oh, forcing jojo too hard to really like hyeyong, but still didn't work.