Tiffany's birthday celebration started, just a casual conversation and a dinner, they invited other Sanbaenims like their SuJu Oppas but they couldn't come because of their tight schedule. That's why only Jang Geun Suk is there to celebrate with them, the girls really like him for Yoona, at first they are only staring at him, he and Yoona are seating next to each other, Sukkie cant stop to worry about Yoona because she's sick, he told her to eat more and take a medicine after eating. The Yuri starts to tease them;

Yuri: Yah, Sukkie oppa, how was it working with SNSD's Goddess huh?

Sukkie just smile, glanced at Yoona and shyly reply

JGS: ah, its great, she's cool, we always laugh on the set..

Fany: Oppa did you missed her? ah.. I mean working with her..

JGS: yeah, of course, we see each other everyday when we're filming, so its different now..

Hyo: how about our Yoong, yah Yoona did you missed Sukkie Oppa?

Yoona: Yah, onnie stop it, its not my birthday, so why are you guys bashing at me..

Tae: she's right, stop it girls, so Fany how do you feel about this two friends of our?keke

Fany: they like a real couple, keke

Yoona: Yah, onnie, stop it,.. if you don't... I..

Sunny: what? what you gonna do huh? Yoong?

Then Yoona starts to talk with her childlike voice, making everyone to burst into laughter including Sukkie..

Yoona: If you don't stop it, i'm gonna talak to you guys like this for the rest of the week...keke

Sunny: Yah, stop it Yoona, it irritates my eardrum..

Seohyun: Yoona onnie, i thought you're sick, you don't look like..keke

Sooyoung: she used to it, she's having a fever every week, she's already immune...kekeke

JGS: I see, maybe that's why you guys called her Him Yoona..keke

After a good dinner and a fun converstaion, Sukkie decides to leave.  He felt so happy that she saw his Yoona, and have fun with her onnies too.  The girls take her to the door and bid goodbye, when he was about to enter the elevator, he realized that he left his coat on SNSD's dorm. Then inside SNSD's dorm, 

Fany: oh this is Sukkie Oppa's coat, yah Yoong, faster give it to him, he just left maybe he's just right at the elevator.

Yoona rushed outside and look for Sukkie, suddenly someone grab her hand and take her to the emergency exit of the building. She just realized that it was Sukkie, he's hugging her tight, she felt happy and hug him back, "It feels good, i miss you Yoong" "I miss you too Oppa" then she feel worried and slowly moved away from Sukkie, but he still holding her hand " Oppa, i need to go, my members will get worried" They checked the door but its locked, so they walked down the stairs holding each others hand tight. While walking Sukkie can feel the warmth of Yoona's hand " It feels good holding you like this, if I could just hold you're hand if i want to, if i could just hug you everytime I want to, If I could just kiss you if I want too" Yoona felt Sukkie's sadness, then they reach the last exit,  "Oppa, mianeyo, I know how you feel, If we could just tell them about us, it wouldn't be this hard" then Yoona stared at him with a teary eyes, Sukkie then kiss her forehead "Yooong, "Love means never having to say you're sorry" the he kisses her lips "I love you my Princess, don't be sad, and get well soon ok? don't get used to it, Its hurting me" Yoona hug him one more time and bid goodbye "I love you too Oppa, drive safely huh? call me when you're home' Then Yoona get's out first and go directly to the elevator and get back to their dorm, while Sukkie took the other exit directly to the parking lot.

When Yoona got to their dorm, she told the memeber's that Sukkie already left and she goes down to the lobby that's why she takes too long to get back.  1:00 am Yoona goes out to the kitchen to drink water, the she saw her Sooyoung onnie staring a glass of milk, he hugs her from the back just like she always do "want a glass of milk too?" "of course, Onnie? is there a problem, you seem so serious" Then Soo get a blanket and take Yoona to the berranda, they sat on the bench and wrapp them selves with the blanket. Yoona felt that there's really something wrong with her onnie, 

Soo: You're still hot, do you take your medicine earlier?

Yoona: Yeah, but I'm fine onnie, I'll be ok tomorrow, thanks onnie

Then Soo hold her hand...

Soo: Yoong, don't you have something to tell me?

Yoona: huh? (she felt worried while staring at her onnie's eyes)

Soo: I saw Sukkie, kissed you while waking you up earlier, i followed you too when returning his coat, and I saw that he grabbed you and take you to the emergency exit..Yoona are you two dating?

Yoona; O..onnie, mianhe, I really don't know how it happened, but..I'm really happy now...

Soo: Don't be sorry, I understand you, but you two should be careful...I don't want you to be cursed..

Yoona: Thank you onnie, I really want to tell you guys about it, but I don't have the courage...and I've also been warned by the management not to be so closed to him because it can affect City Hunter 2.

Soo: It will be hard for you two, but if you really love each other, you need to be careful, I will always be here for you..ok, for now let's just keep it to ourself huh?

Yoona felt happy hearing this from her Sooyoung onnie, she's really thankful that she had a onnie like her.