SISTAR's Bora recently uploaded a picture with Girls' Generation's Sunny and f(x)'s Amber.

On May 22nd, Bora tweeted, "I found my long forgotten family! My 'Invincible Youth' family. Soon Gyu, and Eun Young", along with the picture above.

Amber emphasizes her playful characteristics as she sticks her tongue out while Sunny and Bora are both pouting at the camera.

All three girls were at MBC's 'Korean Music Wave in Google' concert last night and the girls developed their friendship while appearing on KBS2 'Invincible Youth 2', but Amber recently stepped down from her place on the show in April.

Source & Photo: SISTAR's official Twitter