You have a crush on your best friend, sometimes enemy, Key. Well then, you just thought “This is just a fling. As time runs, I’ll like someone else.”  

But, what if someone who is much better than you, more beautiful than you, came and took your place as his best friend, or a better role, his very first love?

As the times passed, you became more and more further from him.

What will happen with your friendship with Key?