Clearly, the women are playing younger versions of themselves in the drama, going way back to their carefree school days. From the way they are amicably posing together, it would appear that they play good friends in the series, though perhaps not without some conflicts or friction as some of the pictures allude.
A rep from the drama's production crew stated, "Kim Hyun Joo, Park Si Yeon, and Kim Jae Hwa's chemistry is simply 'Fantastic.' The trio's steadfast 'womance' will be one of the most fun things to watch for in the drama."
You can catch this 'womance' for yourself when the drama airs this coming September 2 at 8:30 p.m. (KST)!