Joo Jin was the school council and he was assigned to watch over your class on PE. He usually helped everyone with things such as an injury, lost things, or he simply took your jewelery/phones in his hands so they could be safe. Today, u went to the girls dressing room, after a few minutes, Joo Jin entered, seeing all the girls dressing up but he didnt seem to care, he was just secretly glancing at you as he took all of their jewelery in a basket (which he would return after school).