I read the entire thing from the beginning, and can't believe the newest chapter was this cliffhanger.
There really isn't as much info about the girl at the end. We only know she was one of Sensei's students. I wonder what went wrong between them? Whatever it was, I am sure it wasn't romantic, but it may have been serious enough for sensei to switch schools. Damn, I so want to know.
Thank you scienceyscans for the scanlation