Nayeon was an extroverted girl, she had many friends and among them was Jeongyeon, Jeongyeon was autistic and serious, she was cold and introverted but she had an anxious attachment to Nayeon.

They were in math class and Nayeon was doing the exercises on the blackboard while listening to music in his headphones until he heard the teacher speak.

"Jeongyeon, can you solve exercise number 3?"