if you see the teaser, when members return on dorm they shock because something in their bed, it's actually gift and letter from Sakura . (check pic 3) in Chaeyeon bed is Shirt and letter, make possible Chaeyeon crying so hard because Sakura letter for her 😭😭 . Sakura so sweet! That's why Chae fall in love to Sakura 😂😆 .