@TeamLeewon i get where you are coming from but like from sejin's view point i think he doesn't know how to express his emotions well because all his childhood he was never allowed to be greedy or selfish causing him to be the way he and the things you start doing from childhood till adulthood are engraved in you and are really hard to change so i don't think that this arc was useless as it shows how slowly but steadly sejin is learning how to express himself better and to figure out what he wants. This arc shows sejin's character development rather than kwon ido getting him back.