In the unknown future, Keiko Town is an over-industrialized stretch of blackened factories pumping out thick layers of smoke that cast it in a perpetual state of semi-darkness. The citizens of Keiko Town fare no better and walk around their dilapidated town in a stupor of hopeless despair. In an abandoned factory in an obscure corner of town lies the secret base of Hikari Club. The teenage boys of Hikari Club despise the adults of their community and have taken it upon themselves to eradicate what they perceive to be the evil and filth of the grown-up world. To accomplish this, they build a machine with artificial intelligence and dub it “Litchi”. However, with the boys on the cusp of puberty and turning into adults themselves, their own world has begun to collapse around them.