Jonghyun and Key had been best friends almost as long as they could remember. They were always together and told each other even their smallest and deepest secrest. They had promised to stay with each other forever. That promise had lasted, but when they were at their last year of high school, it all changed.

And it stared when a new boy came to their class. He was called Woohyun. First it didn't affect anything, but then Key started to spend time with him. A couple minutes turned to hours then to days, even weeks. Jonghyun was left alone. He didn't understand why Key had left him like that and his life was turning upside down. Then he found a new friend as well. A girl named Shin Sekyung.

When Jonghyun started to spend his time with Sekyung, his and Key's terms got even colder and everything they had once had was starting to fade away. Jonghyun could still see that Key was somehow heartbroken...Why had Key left him for Woohyun at the first place anyway?