Lee Donghyuck is a typical high school student who has a hopeless crush on his upperclassman, Mark Lee. One day, he secretly takes a picture of Mark and sets it as his phone lockscreen. But it seems like the universe isn't on his side because he suddenly lost his phone that has Mark's picture as the lockscreen! Oh no! This is surely a disaster!

Mark is known as a kiss maniac in their section because he loves kisses. Some of his classmates were already kissed by him except his fellow classmate and close friend, Lee Donghyuck. Donghyuck frustratingly wonders why he is the only one who hasn't been kissed by Mark. Is it because he doesn't have plump red and soft lips? Why? One day, he finally gets his answer.

That should be him, holding his hand. That should be him, making him laugh. It's supposed to be him yet it's too late and impossible to happen.

Haechan is a fanboy of NCT U and hardcore Taeyong stan. One day, he gets the chance to meet NCT and sees Taeyong up close. But he also happened to see Mark and hear his contagious laugh. Oh no! Is it possible for his preferences to change in just a short span of time even though he already declared that he’s a solid Taeyong stan?