Rainbow has announced that they will be debuting a new unit group next year! Comprised of Hyunyoung, Jisook, and Seungah, the three members are currently preparing to debut as a trio next month. For a while now, Rainbow has focused on their variety-friendly members like leader Jaekyung and Woori. As such, they've decided to group up the main vocalist, Hyunyoung, and the other vocally talented members to get the spotlight they deserve. Rainbow is still on their debut promotions in Japan, having released "A" and "Mach", both of which fared well on the Oricon chart. The girls have recently completed promotional tours in Osaka, Tokyo, and Nagoya on December 17th, 19th, and 20th respectively. Source + Photos: Sports Seoul