No one exactly knew the reason behind the tension between Hyunjin and Jisung. Everyone has assumed that perhaps it was just envy of each other's talents, but none of them were close to the unexpected truth. They used to be boyfriends, back when they met in high school and just before their debut. They didn't end in such good terms, which is why when Jisung found out that Hyunjin is going to be on the same team as him. Well, let's say that it was an absolute mess between them.