Hwang Hyunjin is Hwang Yeji's twin, they are brother and sister. You and Hyunjin are currently dating at Hyunjin's house, suddenly Hyunjin's older sister comes, it turns out it's Yeji. It turns out that Yeji also has a boyfriend but they are engaged, you, Hyunjin, Yeji, and Yeji's fiancé were talking in the living room "So when are you guys getting engaged too?.." Yeji asked