Promise (performed by Zero and Ryu Si-won)

nul kyote ae issul ko la ko mal hal su issul kka ku lo ki aen nan no mu pu chok han tae
mu ch'ek im hess ton mal lo nol ka chil su issul kka nut ki chon nol po ne ya hal taen tae
o len si kan ae chi ch'in no lul po myon so on chae na ku le on kot ch'o lom tto ka si
nol ki ta li kae hal sun opt o hang sang ne kyot ae iss o chun non
a mu kot to kat chi mot han na ui sa lang i ni kka
na po ta na po ta chong un sa lam man nal su isso ne ka nol chi kyo chul
ko la nun pa po kat un mit um man opt ta myon
o tcho myon ol ma nam chi ang assul chi to mol la i chaen nol po ne chwo yo hal kot kata
ne pum ae an kyo cham tun no lul pa la pol tte myon mi an han ma um ae mok i mae o oa
o len si kan ae chi ch'in no lul an ko so a mu long chi opt un kat ch'o lom tto ka si
chi kil su opt nun yak sok u lo nol ki ta li kae hal sun opt so
ne kaen so chung hess ton tan ha na ui sa lang i ni kka
na po ta na po ta chong un sa lam man nal su isso nut ki chon ae ne kyot ae cho mol li
tto nal su man iss ta myon
nol put chat ko sip chi man ku kon nol wi han kae a ni ya
chi kum po ta heng pok han nal po ko sip o
chi kil su opt nun yak sok u lo nol ki ta li kae hal sun opt so
ne kae so chung hess ton tan ha na ui sa lang i ni kka
no po ta no po ta chong un sa lam un opt sul ko ya
ka chil su opt nun sa lang i toi o ne kae so mol o chil chi la to

(English Translation)
Can I be at your side forever ?
I should let you go knowing you are tired
Like before, I should not let you wait anymore
With you by me everyday, you became my world
If you do not believe I'll be able to protect you
Then please look for someone better than me
I wonder how much time is left
Till I have to let you go
Seeing you sleeping in my arms
It hurts me more but I have to let you go
Because I'm not good enough
You are my only love
And you will find someone better than me
Even if you are able to leave me earlier
I hope you would not leave so soon
As I want to see a happier you leaving
I cried on the way back wishing you will remember me
I'm afraid I will give up on life
So I hope I can forget you but I cannot
You have been so sad because you had to leave me
Do you regret ?
Please remember to believe in me
My hurting heart calls out to you
I hope you will be there to hold me when I fall
I love you and hope you will be mine forever
The sad look of your face when you leave
I hope that will become a dream
Promise me to come back to me