The first part of the movie where they're still young was beautiful and emotional... The second part made my forehead…
They did not kiss, they did not sleep with each other, and they literally and I mean literally lived for 1-2 days! They KNEW that they couldn't be together so that's why they jumped together in hope to get reincarnated in a same time in whatever gender. That's like...the whole point of the movie. In the train u could perfectly tell that they will kill themselves when they had the age talk.