this is one of the best korean songs ever! :D  Personally I love the transition from the verses to the chorus. It does feel like 2 different songs but I love each part of the song, so I don't mind it. :)
Why does this song start so well and the chorus feels so disjointed from the song? It feels like they're singing two songs, there's no structure...I really wish the music would flow from the verse, because that verse had me expecting brilliant things.