Chaeyeon have a discussion about her project with their team, while Sakura and Wonyoung make their assignment suddenly some people approach her and one of them greet "Sorry we're late." Then Wonyoung saying their name excitedly. They look why Wonyoung became excited, when they exchange smile Sakura start to introduce them "Guys! This is Hyewon, Minju and Yuri." While Eunbi group introducing herself "I'm Yena" Yena start and following with Eunbi, Yujin then lastly "Hi.. I'm Chaeyeon, nice to meet you." Chaeyeon said while she tie her hair and exposed her abs. Sakura and Minju face look red when she saw Chaeyeon abs and look away quickly, while Wonyoung squeel at Chaeyeon and say with shyly "Unnie! Your stomach exposed" Then Yujin suddenly grab her shirt while say "I already told you to used my shirt, your shirt is to short." Then Chaeyeon look confuse and say "What? I'm just tie my hair, it's not that I want my clothes to be lifted." 

Suddenly Minju broke their awkward and greet with Chaeyeon while she still blushing "Chaeyeon. Nice to meet you too and thank you for helping me for other day." It made all of them look at them, confused. Then she explain it that the Boys at campus disturb her, Chaeyeon by chance saw Minju in trouble she don't have a second thought that she help her then she disappear without saying anything. "I'm sorry that day I did not greet you, I need to hurry to pick up this kid." Chaeyeon said while her arm are around Yujin. All of them shock with the way how friendly Chaeyeon with Yujin. Who's not shock if at campus Chaeyeon always serious and never smile in front of them. Then Sakura thought "Kid?" suddenly she ask "Yujin! How old are you?" Yujin look at Sakura "Hmm.. 19 years old, Chaeyeon Unnie is 20 years old." Suddenly Hyewon ask "You two sibling?" Chaeyeon and Yujin look at each other look confused and saying at the same time "No!!" Hyewon said again "Hmm.. You two look alike. It's make me think that you must have your parents genes." Chaeyeon became silent, then Yujin start talk again "We don't know what they look like, someone take care of me and Chaeyeon Unnie." H