A staircase leading to a schoolgirls' dormitory usually has 28 steps, but sometimes a 29th step appears. Any wish you make while standing on this step comes true, even if it must come true in the most horrific way possible.

After a surprise visit from her friend Geum-sun, Eun-sim is headed to her hometown with Geum-sun. There, she catches up with Tae-ho who had feelings for her when they were teenagers. Her long-lost memories come to life one by one.