touma and Haruki get on the plane. The two depart Japan. The place where touma had hated because Haruki was there. The place where they had bereaved all of their relationships. They had caused pain, suffering for everybody but themselves. At least they could be happy, right?
touma had explicitly stated that happiness and pain were not capable of cancelling the other out. Happiness will never cause less pain. But because of that, pain can never cause less happiness. Because of that, they’ll be happy. But at the same time, also in pain. But together — they’ll get past it.
Haruki had forgotten something at the airport, but he supposes, it no longer served much of a purpose — his old guitar.