Girl group Rainbow's member Ji Sook revealed a sexy back figure.

Today, Ji Sook posted on her Me2day, "Jean-sook" along with a picture.

In the picture, Ji Sook has her hair to her sides, making a cute face. But unlike this cute face, she is wearing skinny jeans and tied up white shirt, revealing a sexy back figure.

Internet users who saw this commented, "Her line is alive!," "I'm jealous of her ant waist," and "Sexy-sook."

Photo Credit: Ji Sook Me2day