In the story, the player plays the KUI, a 14-year-old girl with mental illness, who falls into her own spiritual world for an unknown reason during a daily activity. Players must pass through puzzles and various strange characters to communicate. The player's attitude toward various items in the game will affect the outcome of the game.
In the barren wasteland on the brink of extinction, the last Train departs, supposedly carrying its passengers in search of a place where they can survive. A creature named Eilf boards the Train, determined to travel to Spring - the station that has been said to have vanished.
Waking up in the darkness, unable to see the sunrise, he remembered the little master carefully carried him home. The base has already fallen into ruin and there are no signs of any living people here. Where did the little master go? Is there any hope left under the doomsday?