After School's Nana revealed a seductive picture of her back.

On June 19, After School's fan website revealed their music video's behind-the-scenes photos of their 5th Maxi Single, Flashback.

The picture revealed shots of Nana's sexy and powerful performances, gaining much attention from internet users. The music video is becoming a bigger issue because the director, Kim Jung Hae, is also the director for Big Bang and 2NE1's videos as well.

After School will be releasing their song, "Flashback" on June 20 and will release their full album on June 21.