Supernova and SNSD are back in Japan already.
According to Supernova's Sungmo to his twitter account.
"내일이면일본을다시가네요^^ 내일봐요!!^^" Jan. 23, 2011
"Tomorrow we would be back to Japan. See you tomorrow!!^^"
Supernova will continue their promotion for their new album SUPERNOVA BEST that will be released on January 26. SNSD will continue their promotions for their Japanese version of Run Devil Run. Sones and Milkyway are hoping for the good outcome for their promotions.
Source: http://twitter.com/Romeo2123 and http://starlight.i9th.com/