(Yet another) Patema Inverted world interpretation

WARNING: THIS POST CONTAINS MAJOR, SUBSTANTIAL, JOY-KILLER SPOILERS FROM THE MOVIE.
[(Edit: Apr, 2, 2021) Hi everyone! This post got more attention than I anticipated and a lot of people wrote their own interpretation of the film’s events on the comments. I recommend skimming through them as well, given some are also really detailed. Guess it just goes to show that, despite some flaws, the film did its job of being puzzling and entertaining. Thanks for reading!]