Best friends forever, right?

A new neighbor moved in across the street. When her family went and introduced themselves, she came face to face with a boy. They were only ten years old but became bestfriends right away. Promising never to leave each other no matter what. At age 16 they still held this promise but now feelings were involved. With multiple problems trying to get in the way of the relationship they don't know if they should keep their promise any longer. What will happen to the two teens.