Land of the Lustrous is set in a distant future where the remnants of humanity live on in a realm inhabited by "jewel people" known as the Lustrous. The Lustrous are gems that take humanoid forms, each with their own distinct appearances and personalities. They are organized into different classes based on their assigned gemstones, and must protect themselves from the Lunarians, mysterious humanoid creatures who attack them in order to harvest their bodies for use as decorations.
The story follows Phosphophyllite (Phos), an androgynous gem of the lowest class who is deemed too brittle to do any work and is instead tasked with creating an encyclopedia about the world they live in. As Phos tries to make sense of their world, they meet new friends, uncover secrets about the past, and ultimately discover a way to fight back against their oppressors.
