Sojung takes pride in being the leader of a group of 13 loud-mouthed girls. That means that she has to know everything that goes on within the group so that she’s able to solve any problems between her members and to take care of them - just like a leader would. One thing, however, Sojung doesn’t understand the relationship between Hyunjung, Jiyeon and Luda.

Or

3A just seem to be switching girlfriends with each other and Sojung doesn’t understand.