The two SNSD members got feisty in the boxing ring.

In the JTBC show "SNSD and the Dangerous Boys", the two led a game where participants were asked to relieve stress on the sandbag. During the process, Yoona and Sunny 'fought over' the sandbag, and Yoona whined to Sunny "It's not fair that you always pick on me!"

This caused them to leave the sandbag and 'throw punches' at each other instead, putting on a feisty little cat fight.