^
I'm not talking about actual love that ofc has to develop over time but for Emiru to even start the peeping agreement with Kidou she had to be attracted to him somehow. Otherwise she'd be pictured as a sexual maniac that would've done the peeping deal with just anyone, which btw, if I remember correctly, was one of Kidous misconceptions as well.
@BladeEntity: I agree that without the peeping Emiru probably wouldn't have opened to Kidou and naturally the author uses the peeping as the main feature to forward the plot, so my scenario where Emiru just starts a normal relationship is very abstract. Still, as mentioned, without their natural attraction to each other the peeping hole would have been closed long ago one way or the other.
To go back to your initial question what would remain if the peeping was taken away. I think the hole, while it helped in actually forming this looming romance is becoming more and more an obstacle for Kidou x Emiru. The single first reaction however would be obviously Kidou starting to miss Emiru, maybe even realizing his feelings once again, which would be a good incentive to start something serious with her.
Assuming his relationship with Madoka is already doomed (which I deem reasonable), in order for the relationship with Emiru to go a step further they'd have to get past the peeping somehow. Not entirely though, I could pciture a last chapter where both are living together in one apartment but retaining a peeping hole within it, such as in the bathroom - as some kind of souvenir from times of them getting to know each other... or just a fetish device
