Yoshiko is a diligent high-schooler who barely has any leisure time due to her commitment to assisting a shut-in childhood friend and a strange, solitary uncle. During a visit to her uncle's luxurious penthouse with two companions, Yoshiko spots a black snow-like substance falling from the sky, yet her friends perceive nothing. Shortly thereafter, an enormous earthquake rattles the city, and Yoshiko, her friends, her uncle, and his dog become stuck in a peculiar, unrecognizable realm...with a diverse group of eccentric individuals as their companions.
