Park Nana, Yeji and Kevin Woo are bests friend since they could remember.

They spend together for very long time and suddenly both of Nana and Kevin got together, leaving Yeji alone heartbroken.

But it wasn't long until Kevin decides to leave for Korea and live his dreams, but that was when Nana found out that she was diagnosed with cancer.

Kevin left without knowing, he debuted in U-Kiss when Nana left the world. Since he left, Nana would always sends him emails. 

Nana asked Yeji to continue writting, without letting him know and she would never love Kevin. 

Due to her love for both of her sister and childhood friend and crush she would do anything.

But what if he came back to US just to see Nana?

How would she tell him that Nana was gone?

How can she love Kevin without hurting him?

But when a sudden question came out of him that makes Yeji's existence much more clearer.

But will she accept that he loves her sister not her?