The movie takes its story from Taku Mayumura’s science fiction book Nerawareta Gakuen, which first came out in 1973 and has been reworked into TV shows and movies before this. The ideas about the future—like traveling through time and a changed Earth—are remarkable when you think about how old the original story is. It's really enjoyable to watch and listen to, with beautiful animation, intricate settings, and sound …