Cocona, an ordinary schoolgirl who lives with her grandmother and uncertain about her future career, meets a peculiar girl named Papika. Along with a robot named TT-392, the two girls fall into a tunnel and wind up in a snow-laden world known as Pure Illusion. Just as Papika informs Cocona that she is searching for a treasure somewhere in Pure Illusion, the girls suddenly come up against giant snow-covered beasts, with Cocona losing her glasses in the process...