In the future, commercial nuclear fusion reactors have become a reality, but a world war destroys them all and causes civilization to collapse.
A society without electricity is more fragile than one might imagine, and humanity is now barely surviving by relying on small renewable energy power plants scattered around the world and lost technology (relics) that cannot be produced.
And no one has been able to restart a fusion reactor that has been shut down. This is because, in order to start a fusion reaction, the fuel must be heated to over 100 million degrees, turned into plasma, and then sealed under ultra-high pressure. This process requires an enormous amount of initial energy, enough to require a "power plant to run a power plant."
Humanity today has no means of creating such a thing, except for one person: a girl named Mitsuha.
CODE::LUX is a multi-ending, post-apocalyptic short adventure. Part visual novel, part rogue-lite, part choose-your-own-action adventure, see the journey of a villainous man and two innocent girls come to an end.