Actress Joo Ah Min revealed her surprising friendship with f(x)'s Sulli via a recent Twitter post. On March 15th, Joo Ah Min uploaded a picture with the caption, "Our maknae Sulli is still 18. I'm so envious and she's so pretty! We took a picture together like we're not even 10 years apart. Our Sulli is mature and I'm not old yet, hehe." In the picture, Joo Ah Min poses in her red tracksuit while Sulli stands next to her, bundled up and smiling warmly. Like any high school girl, Sulli shyly displayed a 'V' sign. The netizens commented, "Sulli is so pretty~", "This is a surprising friendship", and "Both of you are very pretty". Source: TV Report via Nate