Kyuhyun, Jeongmi, Donghui. The three of them were bestfriends since childhood.
Staying together as friends might be a good and easy way to stay happy forever with feelings untold. All they have to do is to just be friends and nothing more.
However time spend together as friends will slower developed into something more then friends. Not everyone can tolerate to hide their feelings forever. The urge to have the one you love to be always yours and only yours. The desperate feelings to have someone by their side forever. Also, there're friends who hide their feelings in order to protect their friends, in order not to get in the way of their relationship. When feelings gets clearly to each and everyone, there's always problems that pops out, getting in their way to become a couple.
The hardest thing to do is to watch the one you love, loving someone else instead to you.
The cause to the pain is,
those hidden feelings...