Dear Gene
This was so heartbreaking Good comment to explain the outcome: He gained the life experience he needed to finally stand beside Trevor and not below him, should he want to return to his side. He needed to step away to do that. Otherwise, he still would have been the child Trevor helped guide. Essentially, he needed to fly with his own wings, and Trevor realized that. This manga, in my opinion, is so beautiful because it includes a variey of relationship types, including a healthy separation. Two people can cross paths, grow, and walk forward. And it does not need to be soul-shattering. It is typically difficult for two people who have loved so passionately to realize that loving each other does not mean constantly needing each other, but love comes in many forms and presents itself in many ways. Like Trevor and Karen, two people once in a romantic relationship can find a healthier, even more beneficial friendship within each other.
Rumspringa no Joukei