Check this video uploaded by 1966chiaki on her YouTube channel.
Yah, it would have been really nice to see Hyun Joong perform live like this.
Btw, according to Steven Lee's tweet 17mins ago...
RealStevenLee: Kim Hyun Joong is now #1 in Oricon Japan Single Chart today, selling 130k copies on the 1st day of release!! YAY THANK YOU SO MUCH!!
Congratulations Hyun Joong!