So I guess the only secret left is why Ichika is looking for that place. Why would she have memories of it? Could she even be the daughter of Kei and Mizuho after all and she wants to see the place where her parents first met? I just checked and the place where Mizuho landed in Onegai teacher has indeed trees and a lake.
Again, sry if this was all mentioned, I didn't read the thread from the beginning
