Two very talented young ladies
Min Young = Black
Hyo Yun = Yellow Stripes
I believe Hyo Yun is part of that 'Gigantic' girl group under SM. "female version" of super junior.
If you want a little more info on them, go here
http://www.hiphoper.com/03d/doc/03d_dt_detail.asp?idx=48
Home » プレイリスト » Youtube » Little Winners - Lee Min Young, Kim Hyo Yun (rehearsal)