Tiffany and Kris was getting ready for their engagement party. Seohyun and everyone there was helping out. Seohyun almost fainted when someone was there to catch her and said: If you keep being like this, who will help you when I'm not around. 

Kris seohyun said.

Seohyun: Thank You Kris...Oh your finish dressing up for the engagement party.

Kris: Yeah...um..Seohyun are you alright?

Seohyun: I'm fine, I just step on something that why I almost fall down but thank to you.

Kris: okay...

Hurry and go to Tiffany she waiting for you. And go welcome your guest that will be coming. seohyun said.

Then Kris go away feeling sad instead of happy that today is his engagement with Tiffany. Tear were falling from her eyes when she looking at Kris walking away happily and say: 

It yours Engagement today but it My goodbye to you...:(

Then she go help set all thing up and Luhun take her to her house and she change into a white outfit for the party. Then Luhun offer his hand to her and they both walk out to his car. They both drove to the Party. Yoona and Taeyoen both wear beautiful dress and come with Baekyung and Kai. Yoona was with Kai and Taeyoen was with Baekyung.  They all went to sit at a table and Tiffany and Kris join them. 

Kris/Tiffany: Thank for coming guy

Everybody: No problem, you two are our friends

Kris look at seohyun and was amazed by how beautiful she is but she seem sad like there something she hiding from them. But Kris quickly look away when she look at him and say: Congradualation!

Kris: Thank You

Kris: Seohyun, I would like you to play a song on our engagement party.

Seohyun: really? Okay...

Kris: Yeah...

Tiffany: Yeah...seohyun..thank you for always helping me and kris. 

Seohyun: Welcome and since both of you are my friends.

Then Kris and Tiffany both go to welcome guest that were coming. And Kris went to the restroomleaving Tiffany by herself welcoming the guest.

IN THE RESTROOM:

Kris: Why am I feeling sad even today was my engagement party? Have I not love Tiffany anymore? Why do I feel jealous and mad whenever I saw seohyun with another guy? Have I fallen fall her instead of Tiffany but never knew it? And why does Seohyun seem sad and act so different from the Vacation? Just be happy kris today is your engagement party. 

after that Kris went out of the restroom and go back to tiffany and Tiffany can see that Kris eyes is little red. 

Tiffany: Kris, did you just cry?

Kris: No, there  was something in my eyes when I went to the restroom.

Tiffany: Okay

After they welcome the guest, they both go onto the stage and annouce their engagement. 

Kris: Hello everyone, Thank You for coming to my Engagement Party. I'm really happy now. Were having this party so that we were engage when we went to school and after we finish school, we are planing to get married. We hope you can come to out wedding too.

Tiffany: Hello! I'm Tiffany and today I'm really happy and hope you can come to our wedding too. Thank you for coming everyone.

Everybody clap. Then Kris put the ring onto Tiffany hand and Tiffany also did it too. Everyone shouting for them to kiss and Kris kiss . Everyone clapp. After that Kris annouce that seohyun will go play a song on the piano for their engagement party. Thank you

Seohyun: Hello everyone, I'm their friends and I'm gonna play the piano for them. 

Everyone was sitting down listening and looking at seohyun playing the piano. Then people start to get up and dance to the melody of the song seohyun play on the piano. Seohyun was crying as she was playing it. All the light was gone but only one on and light shine on seohyun playing the piano. She start to since with the piano playing. Everyone cry because of her sad song because it describe how this girl love her childhood friends but he doesn't love her and married her bestfriends instead and later realize that he love her not her friends but it too late because the girl already dead. After that everyone go sit down and clap their hand and wiping their tears. Kris was hurt by the song and piano she play because he felt like he that guy and seohyun was the girl. Kris was crying and Tiffany too so they both wipe each other tear while seohyun staring at them. Seohyun leaves without Kris and Tiffany notice but she tell Yoona,baekyung,kai,taeyoen, and Luhun goodbye and hug each of them and tell them about her sickness. The Party end and Kris was finding where seohyun was but can't find her. Until he bump into his friends and ask where seohyun was but they didn't tell him until yoona give him the letter seohyun leave for him. And he open it and read with everyone there.

The Letter:

Kris please don't look for me because when you read this letter I'm already gone. I went to America with my parent and brother. Thank you for being such a good bestfriends for me. 

Kris, I have like you for a long time and that why I'm always there to help you and do anything for you even if I'm hurt but you never see it until now that I'm have give up on you already. You still remember that day that you ask me to help you with Tiffany. Actually i was going to tell you that I like you but hearing what you say broke my heart and I decide not to tell you and help you with Tiffany if you like her so much. Everything you hug me or compliment me I blush but you never saw. Kris you also remember the day I didn't come to school after you told me you like tiffany right. I was crying the whole night thinking about that and it when I found out that I have Brain Tumor. I feel bad that I have to lies to you on why I don't come to school. And you know when we accident kiss, I felt so happy but seeing your face when that happened I felt so bad and sad that I have your first kiss not Tiffany. And I didn't come to school last day of school was because I go to the hospital for a check up. And when you saw me at the bookstore, I was looking at those book because I'm sick so that I will know how to treat myself to stay longer to see you being happy then I will leaves. And the Vacation was fun. You remember when you say that me and Luhun look good together. I decide to date him because of you. I willing to do anything for you even if I'm hurt as long as your happy. My sickness was getting worse from the vacation and seeing you kneel down at the airport asking Tiffany like that, make me jealous that I wish I'm that girl. And remember where you catch me when I was about to fall down awhile ago, it was actually because my sickness is getting worst and almost fainted but you catch me. I feel happy but sad too. And when you ask me to play the piano, I felt happy because I can do something good for you and Tiffany before I leaves. I'm sorry if my letter to you here is about my confessiong. I feel embarassed when I write this letter.

Oh! And if I'm still alive I will comeback to attend your wedding. 

Goodbye!

sincerely: Seohyun

Tear were falling from everyone eyes and Luhun. Tiffany felt bad and sad. They cry like they felt the pain she go through. Kris feel hurt, sad, and bad that to this day he never saw her love for him and even lead her to having a Brain Tumor that now he just realize how much he love her. 

Flashback:

After the vacation, seohyun went home and tell her parent she want to go to america and get treatment for her sickness and they were really happy.

Seohyun: mom, dad, and Siwon, I decide that I'm going to america with you all to get treatment for myself. 

Mom: really seobaby?

Seohyun: Yeah mom, I don't want to died because I still want to live with you and dad and siwon. We will start our new life there in america when I back to normal and not sick anymore.

Her family: Okay, then tomorrow we will leaves at night after the engagement party of Kris and Tiffany Ok.

Seohyun: How do you know it their engagement party tomorrow?

Siwon: Kris call and told us.

seohyun: Oh..

Family: Okay, pack our things for tonight and save some clothes for us to wear tomorrow after the party to got to america. 

Seohyun: okay!

End of Flash back.