This story is about a guy named Kim Jongin also known as Kai and a girl named Lee Boona (You as Boona). The two of them have been best friends for three years, they know each other a lot. Their likes and dislikes. In class, he is famous because of girls liking him. They compliment him, they get close to him and that made Boona felt insecure.

She likes Kai since they became best friends, she hides it because she doesn't want to ruin their friendship. She tends to get a little jealous everytime he plays and jokes around with this girl in class... They do seem close... She jokes around with him too. Sometimes they look like a couple because Boona saw him touching her back like he meant in...

Will their friendship end?

Or will Kai feel the same?