He first met Yerim when they were made partners for Taekwondo. 

Being new to the neighborhood, his parents enrolled him for Taekwondo lessons at a local dojang in hopes of encouraging their only son to make new friends and build up his strength, for Jungkook was a very timid and fragile child.

He remembered his first impression of Yerim that day. 

Master Kim had him stand before the class to present himself to his peers; there were three students in total. After struggling through his introduction that consisted a lot of "um's," Master Kim quickly ushered him towards the others to begin class. 

Jungkook quietly stood next to an older boy who wouldn't stop smiling at him. The boy wore a stupid expression when he introduced himself. Hoseok was his name. Apparently, he could simultaneously drink yogurt and perform a handstand all at the same time.

He made a mental note to stay away from the older boy throughout the duration of their lesson. 

The other boy to Hoseok's right fashioned the traditional mushroom haircut. He also appeared too preoccupied with the large mirror behind them to pay any real attention to Master Kim's lesson. Jungkook later learned that Jin was the oldest of them all. He thought Jin was a very mature person for his age, but his first impression of the boy shattered when the old ladies next door had laughed about his unhealthy obsession with himself.

And then there was Kim Yerim. 

She wore two pigtails that day. 

As Master Kim's only daughter, she was the most experienced out of the three current students. As a result, her father had paired them together for the next lesson. He remembered they both stood at the same height, which made avoiding eye contact entirely impossible. Even after bowing to one another, she would continuosly stare at him with large and curious eyes. Not used to the attention, he nervously fidgeted in his place. With his mind distracted, he missed out on the instructor’s lecture and demonstration of a proper Taekwondo punch. Also missing the 'go' signal from Master Kim, Jungkook was made unprepared for the next event that soon occurred: Yerim punched him straight in the face.

Loud laughter escaped from Hoseok's lips and Jin had even managed to tear himself away from his reflection to see what happened.

Shocked and in a daze, he felt warm blood trickle down his nostril. There was a miscommunication between his brain and body, so rather than quickly reacting at the impact, he just stood stock still as his partner slowly retracted her fist from his face; her eyes still wide in observation. The pain that he should've felt earlier had suddenly rushed to him all at once, causing him to clutch his nose.

Jungkook began to cry.

After 15 minutes of calming down and ten used tissues later, he finally stood before the girl once again with dried eyes and a thick wad of tissue shoved up his nose. He stood with resolve and stared at his partner with a determined expression, vowing to never cry in front of Kim Yerim again.

However, he would later regret this promise when they both become older.