Do you dare to climb the 29th step?
In a Korean boarding school, there is a legend about its twenty-eight steps stairway: when the twentieth-ninth step appears, the fox will grant a wish to the climber. The lesbian ballet student Kim So-hee is in deep love with her passive girlfriend and also ballet student Yoon Jin-sung. When there is a competition for a single spot in a famous ballet school in Russia, the envious Jin-sung finds the twentieth-ninth step and asks to beat the favorite So-hee. However, there is a price to pay for the wish unknown to Jin-sung and the consequence is the accidental death of So-hee. Meanwhile, the fat student Eon Hae-ju, who is despised and tormented by her classmate Han Yoon-ji, misses So-hee. When she also finds the mysterious step, she wishes the return of So-hee with tragic consequences.