SISTAR, one of the most successful girl groups of 2012, shed tears during a recent filming of Mnet's 'School of Rock' 'energy attack' special.

The members appeared on the program to surprise middle school and high school students with a mini-concert. Hyorin, Soyu, Bora, and Dasom showed up to give the students a little rest from their stressful studies.

However, even after their performance, the girls received a cold reception. The students didn't react, simply staying silent. The SISTAR members were taken aback, and they eventually showed tears.

It wasn't what it seemed though because the students then surprised SISTAR with a performance of their own.

This special episode will air on Mnet on January 16th at 8:30PM KST.