Hyunmin and Mika sing 'I promise you ' originally sang by Wanted( 원티드) and Lee Jung ( 이정 ).
Gosh, their deep and husky voices *-* Such a talented guys really, and such a wonderful cover *-* 
credit: all rights reserved goes to the rightful owner of the video and to the rightful owner of the picture. 

source :Youtube.com

live  from 20.03.2010 

(video in the picture. )