One day, Hyun-soo discovered a little girl trapped inside a house through a window in one neighborhood. There, she meets Min-ha and starts hanging out with her every day at 2:15 p.m. for exactly 15 minutes before Min-ha's scary dad returns home. Min-ha has one wish: to go to the playground. And meanwhile, Hyun-soo's mom decides to send her to Canada, where her aunt is. Therefore, Hyun-soo decides to take Min-ha to the playground for the first and last time, but the two weren't aware how much this day would make them miss each other.
