The "nation's little sister"�IU held her 'Real Fantasy 2012' encore concert on the 22nd and 23rd.

At the concert, she previously received attention for dancing to Psy's "Gangnam Style" and now she's receiving attention for performing a dance to Britney Spears' "Circus".

During the "Circus" dance, IU came onto the stage in what seems like just a large men's button up shirt, causing the crowd to cheer loudly. However, she was in fact wearing black short shorts underneath.

Check out IU's�"Circus" stage below!