The korean girl group After School from Pledis Entertainment which debut on 17 January 2009 with their first single ''Ah'' with 5members Gahee, Jungah, Jooyeon, Bekah and Soyoung. Right after that, UEE was added in the group and formed a 6members girl group. In the end of year 2009, Soyoung left the group due to her heath problems and then replaced with two members Raina and Nana by releasing ''Because Of You'', this song has been topping various music charts.
After School's Bang! that just released no longer ago gained a lot of attention from Kpop fans. The blue marching band uniform is a huge difference unlike the dark trend of SNSD's Run Devil Run, Kara's Lupin, and T-ara's I Go Crazy Because Of You. So, fans please do not compare SNSD, Kara, T-ara and After School together because they all do have their own individualities and advantages. 
Besides, the choreography from America was sent to Korea and After School has been consulted with their dance team Wawa* to make to make it flawless. We hope that their dance will become a new trend and widen Kpop music to the whole world.
* From BoA, Clon, Taiwan's group F4, SHINee and After School and until Son Dambi's Crazy Chair Dance. They have made the great choreography and are the nation's best dance team.
Let's learn the dance step of Bang!

Credit: Syee22 @ Daily K Pop News