The story takes place in a distant future world. There is a kind of humanoid life form with a body made of gemstones on the earth. Since its appearance, this life form has experienced the tragic fate of being plundered. Now, there are only 28 people left in the world. The mysterious race "Moon People" of unknown origin appeared and began to plunder the gem people, cruelly making them into ornaments, not only that, but even processing them into weapons. Phosphophyllite (voiced by Kurosawa Tomoyo) who is very fragile and has no toughness, Cinnabar (voiced by Komatsu Mikako) who can release silver venom, Diamond (voiced by Chino Ai) who yearns for a romantic love story, Round Diamond (voiced by Sakura Ayane) who is devoted to fighting, Morganite (voiced by Tamura Mutshin) with a lively and cheerful personality, in order to resist the invasion of the Moon People, the remaining gem people in the world decided to join forces.