This arc is getting really good.
Kitano mentions that they "saw Hasumi-san reading a poetry collection when [they] got here", so Hasumi-san got hospitalized over the course the trip. We also have confirmation that bullying is the cause of the hospitalization, with the "putting a target on your back" thing.
What's up with Ena's motivations? I don't see her as the type to do what she did for no reason. Besides, Koharu, who's supposed to be an empath, approves. So, it's not that the two are incompatible or anything. I assume it's because Ena is a very careful cupid, and considers more than love when making a decision. She likely has been on this task for a while, and probably knows the most about the situation out of all the cupids. This would imply that there is something seriously wrong with Kitano and Touma pairing up; I assume the bullying must be really bad.
Also, Ena is really angered by Chiyo's presence. It's kind of funny how most of the fandom thought the four cupids got along; I guess that isn't the case at all. Did Chiyo mess something up in the past, big-time?
I think most people are too quick to blame Touma for his actions. We don't know why he did what he did, first of all. Moreover, Hasumi just got hospitalized and people talk about stabbing each other in this school, so he probably has every reason to be on edge.
Finally, it seems as if Hasumi's bullying only recently got worse: Touma says "we can't do whatever we want anymore". So, what changed exactly?