You and Haechan have been friends since the two of you were in 1st grade of elementary school until now 3rd grade of high school. You two are so close, as are your families, you also spend a lot of time with Haechan

Haechan is your first love, you've had a crush on him since you were in the 2nd grade of junior high school. You never told anyone, only you knew your feelings for him. But the problem is, Haechan still hasn't moved on with his ex-girlfriend, the girl he dated in the 1st year of high school to the 2nd year of high school, even though their relationship was destroyed because the girl cheated on Haechan, but Haechan still can't move on from her.

Haechan also often talks to you about his ex-girlfriends, talks about their past, or tells you how much he misses her. But on the other hand, you try to make Haechan fall in love with you secretly, make Haechan forget about his ex-girlfriend, you do anything to be "the number one girl in his eyes"