In "Who are You: School 2015" the identity of Jung Soo In who had not been active came to the surface little by little. It was revealed that she was not in good relations with Kim So Hyun, which raised curiosity with future activity.

On the 7th episode of KBS 2TV Monday/Tuesday drama "Who are You: School 2015" (script Kim Min Jung, Yim Ye Jin, director Baek Sang Hoon, Kim Sung Yoon) broadcast on May 18th, Lee Eun Byul (played by Kim So Hyun) wanted to find out who Jung Soo In was and therefore called another friend out. These two had met in the past before Eun Byul disappeared on a field trip. Eun Byul said, "Did I meet you before" and tried to recall these memories.

This friend was surprised that Eun Byul's memories had come back. She said, "Have you thought of this?" She asked, "Are you the person that sent me weird texts in Jung Soo In's name?" Of course, Eun Byul received the same text, she did not get startled. Nonetheless, not being able to believe that a dead person Soo In sent a text, she was upset and pushed out Eun Byul. In this process, a tree branch scratched Eun Byul's neck.