Introducing the characters: 

Dahyun - an innocent, bubbly, easy going type of girl. Not so popular but quite well known among the students in the same grade as her. Dahyun hates drama and whiny people. She loves to draw, eat and spend her time with the people she loves. Has a childhood bestfriend who lives next to her house and is in the same class as her. He's the only person Dahyun trusts and he's no other than Im Jaebum.

Jaebum - a popular, charming, good looking guy at school. Has a group of friends who's all also popular. Protects and cares about Dahyun every single day to the point that he's willing to sacrifice his blood than to see Dahyun got bitten by a mosquito. His feelings towards her is more than just bestfriends but she doesn't know about it.