A new life form, the Gems, must fight against the Lunarians, beings who attack them without discrimination and use their shattered bodies as decorations. For this reason, each Gem is assigned a role, whether it be a fighter or a medic. Phos, the youngest of their kin, and has not been given an assignment due to a lack of skill. Everything changes when Kongo assigns Phos the task of creating an encyclopedia of natural history.