On December 9th, Sistar official Twitter wrote a message,"Please give a lot of love for 'The Snow Queen 2'~!!^^ #Soyu #TheSnowQueen2 #Diamond" and uploaded a long two screen caps of Soyu which seem to be from the MV for her upcoming OST.
Soyu will be singing the Korean version of 'Diamond', which is originally sung by Bella Thorne.
'Diamond' will be released through online music sites on December 10th at noon.