I think you have to bear in mind that the school roof is very much a trope in Japanese media - important stuff always seems to happen on them. There is absolutely no way on Earth that Selebus is not aware of that trope and I suspect it is not unreaonable to believe he is doing it deliberately.That school roof is pretty weird:
- Resets
- Blujay
- Baby Finches -
I'm positive that's the beginning of the game- Ayane in the reset
I wonder how many actual Japanese schools have rooves that can even be accessed.