The 8th Day. It is when God creates the imaginary world "Fictional Reality". It is considered to be the place where the dead ends up at.
On every 8th day, all humans are given a chance to retrieve someone from "Fictional Reality" and return that life to Earth. However, the trials aren’t simple. Six people, consisting of two representatives from the past, the present, and the future, are gathered together to start the “Imaginary War”. They must accomplish every given tasks, and only one person, the victor, will earn the chance to [Save].