Yedang Entertainment is preparing to launch the debut of their new girl group, 'CHI CHI', and they've just unveiled the MV teaser for their title track, "Sun". It appears to be a colorful music video, which has the girls dressed in kitschy outfits against a game show-esqe backdrop. Shackled against the paintball wall of doom is actor Lee Jong Suk, whose role in the video we've yet to determine. Lee Jong Suk's cameo in the video is sure to amuse "Secret Garden" fans, since he recently played the role of 'Sun' in the drama. Check it out below!