Yeon Iseul, the top student in her entire school, suddenly starts seeing people???s true feelings as hashtags floating above them.Then one day, her first love, Seong Shinwoo, attaches a hashtag to her:#Trash_That_Used_To_Be_My_First_LoveThe old wound of being dumped without knowing the reason is torn open again,and Iseul joins forces with Baek Seol, a guy who hates Shinwoo.Is this revenge, or lingering feelings?This time, who will be the one to get hurt first?