Maybe I'm crazy, but of late while playing LIL, I've been getting this odd feeling that when the game is completed, we're going to learn that the whole reset thing is a kind of time travel loop that Sensei is caught up in, likely having gone back to 'correct' something he did, and got stuck in. However like Quantum Leap's plotline, due to how the time travel works, he loses all his own memories and ends up with a kind of swiss cheese memory. If this idea is true, then it also could make sense if in a kind of longer version of Groundhog Day (taking place over several months, instead of just one day), that over time situations could happen which might have the people going through it become aware of the time loop. Perhaps the nexus point being the school roof which they have to always go to to 'survive' the reset. I could see, perhaps, Maya stumbling across that in one of the resets, and coming to realize what's going on; then going through multiple versions of Sensei before the 'real' Sensei appears again.
As to how she might stumble across it, who's to say that Sensei himself didn't do the same thing for a while, and then invite Maya up there to meet him; only to not make it up there himself and get locked 'outside' the protective bubble, forcing her to try to figure out what's going on herself. Alternatively, it could be something simple, like a kind of butterfly effect situation where a seemingly simple previous choice Sensei and Maya made saw her up there when the reset happened, and he didn't make it.
The earlier reference to a paradox makes me suspect that in the time we have until around Dec 30 when the reset happens; something is out of place. Above and beyond the weirdness we see with Nao and Kaori, or Yasu. I've often wondered if it'd be a good idea to go through the various 'events' in chronological order, looking for ones that seem to repeat and which should be reasonably similar in regards to the cast involved, and look for something out of place. Though honestly, given the game is a work in progress... I doubt I'd find an answer that way. However, it wouldn't surprise me in the least to see that the answer to what was the paradox, and what was causing the repeated looping, was already present in the story of the game, and it's just been overlooked to this point.