She was at an football match..in the group of her school,there was her enemy and bully…Changbin..and she went here with her boyfriend Jin and a friend…she gets away to get some water..but when she returns..she sees her boyfriend and best friend on the kiss cam..kissing passionately…the water falls on the ground from her hands and she goes away..crying a bit…Changbin notices this..they had won the match..and as soon as the game finishes..he rushes to her in the bathrooms…he enters and sees her…