The song's in the key of B. Whole song is in the order below. I don't speak 
korean, so I'm sorry if the chords aren't placed at the right times. But its very easy to pick up

  B: x24442
 F#: 244322
Abm: 466444
  E: 022100

   B                    F#             Abm                       E
Neo gateun saram tto eopseo juwireul dureobwado geujeo georeohdeongeol 
          
eodiseo channi
B                        F#                     Abm
Neo gatchi joheun saram neo gatchi joheun saram neo gatchi joheun ma eum 
 E                     
neo gatchi joheun seonmul
 B                   F#                Abm                     E  
Neomu dahaeng iya aesseo neorel jikyeojul geu sarami baro naraseo eodiseo 
   
channi
B                      F#                       Abm
Na gatchi haengbokhan nom na gatchi haengbokhan nom na gatchi unneun 
          E
geureon choegoro haengbokhan nom

 B                 F#           Abm            E
Neoui ttatteuthan geu soni chagapge, chagapge shikeo isseul ttae
 B                       F#            Abm          E
Neoui ganghaetdeon geu maeumi nal karopge sangcheo badasseul ttae
 B                    F#            Abm                          E
Naega jaba julge anajulge salmyeoshi, geugeoseuro jakeun iroman dwendamyeon johgesseo
 B                   F#                 Abm                      E
Eonjena deo maneun geol haejugo shipeun nae mam neon da mollado dwae
  B               F#     Abm              E
Gaseumi sorichyeo marhae jayuro-un nae yeonghon
        B                      F#                 Abm               
Eonjena cheo-eumui imaeum euro neoreul saranghae georeo watdeon shiganboda
   E
nameun nari deo manha

And so on....