While it's true that it's unhealthy for Sayu to keep running away from her problems (literally), it's also true that Gotou seems like a two faced person so far and Sayu's thinking things like "it's like you're hiding your true nature behind it", when Gotou smiles at her feels like it's maybe foreshadowing something
Honestly I don't like how Gotou rejected the MC at the beginning, basically expecting him to keep chasing after her and not going for another woman instead. That kind of attitude is disgusting in my opinion. You can sugarcoat it as much as you want by saying stuff like "oh maybe she just wants to make sure, he really likes her" or shit like that, but fact is that she hurt someone, she claims she likes, just to further her own interests and while certainly is a "good" way to confirm his feelings, it's pretty manipulative and I can't imagine that kind of attitude leading to a healthy relationship, if she's always like that.
I think the best scenario would probably be that the MC helps Sayu face her past and then ending up maybe dating that Kohai of his, who seemed to be honest and sweet so far.