Students at a girls' boarding school test the legend of a mysterious staircase that is said to grant wishes once a secret step is revealed. Park Han-byul, Yun Jae-yeon, Song Ji-hyo, Moon Jung-hee, Hong Su-a, Jang Wu-jin, Park Ji-yeon, Jo An, Ji-min Kwak, Ji-hyo Song, Han-byeol Park, An Jo, Ji-Yeon Park Added on Netflix 2023-01-10. Youtube Trailer