f(x)'s Krystal looked casual and sexy for the May issue of 'CeCi' magazine. The theme was appropriately called 'Blue Confidential' as she donned denim in all of the pictures, showing off the great body line that earned her title of 'Denim Muse.'

SEE ALSO: ILLIT member Wonhee already lands a big CF deal just weeks after debut

Associate Editor Cha In Sun, who was present at the shoot, said, "The shoot did not show off sexiness that arises from excessive exposure of the skin or through purposeful directing, but rather sexiness from the energy that Krystal gives off."

Jessica and Krystal's reality show 'Jessica&Krystal' will premiere on May 6 at 11 PM KST! Check out the full pictorial here!