Best "Friends" with Yang Yoseob

Park Sanha was always called a nerd. She always wore wide rimmed glasses and liked to read books ever since she could read. People thought she would never have friends. But one day while walking to the library when she was five years old, she got bullied around by older boys. She didn't know another boy watched from afar. When the bullies ran, he was the one who helped her, comforted her, and had been there for her. They were inseparable. That is until Sanha's father for a job in the US. That was when she had to leave her best friend.

But that was when she was 5 and he was 7. Now their grown adults and have their own lives. Yang Yoseob was a vocalist in the group Highlight while Sanha loves in the US and works at a book company. While having a break from doing music, Yoseob went to the US to have a little fun in a different country. Yoseob finally meets Sanha after all these years and has grown to love her again. But he still thinks she sees him as a friend.

What happens when they live together after all their years apart? Will they grow to love each other like they used to? Or will something, or someone get in the way? It's like what most people say: Two people of the opposite gender can't really love in close quarters together without having a little tension in the air.