It is based on the novel A Special Day That Comes Only Once In My Life (내 생에 꼭 하루뿐일 특별한 날) by Jeon Gyeong-rin.

These few words take away and shatter Mi-heun's life as she knew it, a true terror on an unforgettable Christmas evening.

Swept away by the peaceful, silent town of Butterfly Ville, Mi-heun and her family begin a new life as if nothing had happened.

As Mi-heun sits blankly under the blazing sun at a rest stop, a sharp voice comes to her like an alarm and awakes her.

The lonely pond remains as Mi-heun is walking through the heavy woods that are found outside the only motel in town.