One day Siwon was walking on the sidewalk until he suddenly received a call. He stopped and reached for his phone and saw that it was a call from his girlfriend's grandfather.

Siwon: Hello?

Grandfather: Siwon?

Siwon: Yes, grandfather what's wrong?

Grandfather: Can you come to the hospital it concerns Moon.

Siwon: Is she alright? Did something happen?

Grandfather: It's something she’s been dealing with since she was a little girl.

Siwon: I'll be right there, you can tell me everything later. *hangs up the phone*

 

-Flash back: Earlier that day-

 

Grandfather: Moon your results have come back.

Moon: Tell me what it says; I want to know why my chest hurts a lot.

Grandfather: *opens and sees the results* I knew this day would come.

Moon: What is it grandpa?

Grandfather: The day that you were born, you were born with a weak heart and the doctors said that you may not make it to your 20s and you are 18 now. I thought that maybe your heart got better now but I see that it's in the same condition.

Moon: Why didn’t you tell me earlier that I had this type of illness?

Grandfather: I didn't want you to worry about your future.

Moon: - Starts to feel pain in her chest and starts to grab her shirt in a painful way while falling towards the ground -

Grandfather: Moon, are you ok? Please answer me!

 

-End of flashback-

 

When Siwon got the hospital he started to ask the front desk to tell him where was Moon's room. But suddenly he saw her Grandfather and started running towards him.

Siwon: Grandfather, what’s wrong with Moon?

 

Moon's grandfather started telling him about Moon's heart condition and while he was listening Siwon started to cry and kneeled to the ground, as he couldn’t believe what the grandfather was telling him.

Siwon: Isn't there a way to save her? - I said while crying -

Grandfather: There is a way, but here in Korea there isn't a hospital whit a B blood type heart available.

Siwon: Wait B type? My blood type is B I can give her my heart. I just want to know that she is alright. - I said while tearing up -

Grandfather: Are you sure Siwon? You’re sacrificing your heart for her. Her destiny was already chosen for her to die with this condition, but you still have a lot to live for.

Siwon: I'm sure, I just want to see her alright and knowing that she would be alive. *sobs*

Grandfather: Well then I'm going to tell the doctors about your decision, but if I where you I would say my last words to Moon before you do this.

 

Siwon's P.O.V

 

As I walk towards her room I started to wipe away my tears and trying to control my breathing. When I walk in I see Moon sleeping on the hospital bed and couldn't hold back my tears and started to cry again. When I got closer to her I sat down on the border of the bed and grabbed her hand. As I took her hand I placed it on my right cheek and started to feel her hands still warm. While I was doing that she suddenly woke up and smiled at me like if nothing was wrong but I knew everything, I started to cry a bit more and with the hand I had of her I kissed it and placed it on my chest and kept crying but with my eyes closed.

Siwon: Moon why didn’t you tell me anything? - I said while sobbing -

Moon: I didn’t know either until my grandfather told me this morning when I got my lab tests.

Siwon: Can I tell you something before we depart? :'|

Moon: What is it?

Siwon: I just want you to know that you’re the one and only person that owns my heart and I want you to know that you will always have a part of me inside of you. :')

Moon: Aww Siwon, thank you for saying that. -Starts to tear up- :')

 

Moon grabbed my shirt and pulled me towards her and kissed me for the last time before we departed for different places. When she stopped kissing me I was still holding her hand, so I kissed it again and left the room. As I started walking to the operating room they started to put anesthesia to Moon, she thought that they were going to try and save her heart but actually I was going to give her a piece of me that she will always have inside of her and will cherish forever. While the doctor was preparing everything they placed us next to each other. Moon was already unconscious from the amnesia and before they gave me amnesia I grabbed her hand so we could have our last moment together before what was going to happen occurred.

While the doctors were doing the operation they received a call that someone in the same hospital that we were had died and were donating their organs and had the same blood type as what they needed they quickly told them to bring it back to the operating room where they already removed my heart and were placing it inside Moon's body, and when they brought back the other heart they quickly placed it on my body. When they finished the operation they told Moon's grandfather that the operation was a success.

He started crying and thinking of what I was able to do for the person I loved for since we were in 7th grade.

 

Nobodies’ P.O.V

 

7 days passed since the operation happened and Moon started to wake up and realized that she was still alive. She saw her best friend and grandfather there in her room but didn’t see her boyfriend, she thought that maybe he went for some exercise and went outside for a bit.

Moon: Grandpa, where’s Siwon?

 

Her grandfather started to cry, as well did her best friend started.

Grandfather: Siwon....*sobs*....isn't.....*sobs*.....coming.....back...

 

Moon later remember what Siwon told her before they departed from the room.

Moon: How could he do this to me? - I gripped the shirt I was wearing were my heart was and started to cry. - How could he!

 

A doctor entered out of nowhere and called for her grandfather to come with him for a moment because he had some important news to tell him.

Doctor: Sir do you know this person. * shows photo of Siwon *

Grandfather: Yes I do? What’s wrong?

 

The doctor explained that while they removed Siwon's heart they had received a call that someone died in the same hospital and had the same blood type of heart that they needed and implanted it on him. The Grandfather couldn't believe what they were saying to him and started to cry tears of joy. The doctor took him over to Siwon, but Siwon hasn't woken up since the operation. The doctor said that it could take more time for him to recover because during the operation he was dead for 5 minutes before we placed the heart they received, because it took time for the heart to settle in. The grandfather was still very happy because he thought he would never find someone better than him for his grand-daughter. As he was walking back to Moon's room he didn’t want to spoil the news until he woke up and kept it a secret for a few days. Moon was very depressed but he didn't want to give up that easily and tell her. As 4 days passed and they were going to release Moon from the hospital and the doctor told the grandfather that Siwon had woken up and he went running to his room and saw that he was there with no problems.

Siwon: Why am I alive? - Starts to look around and seeing his hands trying to know the reason why he’s alive. -

 

The grandfather told him everything that happened during the operation and told him that Moon was alright and that they were going to release her today and she still thinks that Siwon is dead, but he’s going to bring her to him before she left.

Siwon: Is that really true? I can't believe that really happen!

Grandfather: Yes, you were very lucky that day. Siwon wait a moment I'm going to bring Moon over so you can see her again.

 

Siwon was over joyed after he heard what grandfather said. So when Moon's grandfather brought Moon over so she could see that he was still alive she stared at him and couldn’t believe what she was seeing with her own eyes.

Moon: You’re….. still alive! :')

Siwon: Yes :’)

Moon: How could you do that to me, I thought that I lost you forever and couldn't believe that you risked your life for me. :')

Siwon: I told you that you were going to own my heart.

 

Moon was so happy at that moment that she leaned over to Siwon and kissed him passionately while everyone stared at them but she didn’t care at that moment because she couldn't hold it in. After Siwon got out from the hospital, 3 days later Siwon proposed to saying - You're really the only person that has my heart and I want to spend every moment I have to be with you. - Moon accepted proudly the proposal and was very happy of what his boyfriend (now fiancé) did for her.