Well, it's selfish if she asked him to wait for her to pass her exam while knowing they cant end up because of the same surname same clan law. Both of them knew they were too young and there were tons of things more important than love. They knew that their break-up would come soon and always felt insecure because of it.... Actually, I think they did it right when seeing BR ate her mom's crabs so enjoyable and SW's mom cried for his scholarship. If there's no break up, we cant see how manly SW would be for BR or how soften BR would be for him. Their love changed and was strengthened a lot by 6 year separation. And clearly, BR asked to came back after she knew the law was about to change :D
Especially, if there was no breakup, there'd be no hotkiss like this