In the distant future, Keiko Town is a heavily industrialized area dominated by soot-covered factories that continuously emit dense smoke, leaving the town in a constant twilight. The residents of Keiko Town are equally affected, wandering through their crumbling environment in a haze of hopelessness. Hidden within a deserted factory in a remote part of town is the clandestine headquarters of the Hikari Club. This group of teenage boys harbors a deep resentment towards the adults in their community and has taken it upon themselves to cleanse the world of what they see as the corruption and decay of adulthood. To achieve their goal, they construct an artificial intelligence machine named “Litchi.” However, as the boys approach adolescence and the threshold of adulthood, their own reality begins to unravel.