f(x)'s Amber sweetly showed her support for fellow group mate, Krystal, apparently on the set of her current SBS drama, 'My Lovely Girl'!

Amber uploaded a picture onto Twitter of herself holding up a sign that says, "You've worked hard, Princess Jung Soo Jung (Krystal)," with Krystal smiling next to her.  She repeated the words from her sign when tweeting the picture, making everybody go "aww" at their sweet friendship. 

'My Lovely Girl' will be wrapping up on November 6.