In a big city in the desert called Valcia, only young people called 'adept' are allowed to go out. The city used to be covered with a canopy, but people can see the sky and a lot of people visit the city through the canopy now. But this inflow of people gradually changes the city... Young people called "adept" are the ones who search into various ruined labyrinths full of treasures and danger, and fight against monsters called 'horror'. Recently, these monsters called 'horror'", which are supposed to exist only in the labyrinths, started to appear in the city. People are now afraid of the change of the city and the monsters. One night; a boy sees something shiny, another boy learns what to love, a girl finds the meaning of the starry sky, and an assassin sheds a tear of remorse...