The Sailor Quartet sometimes referred to by the fanon term The Asteroid Senshi are manga only senshi. They are four senshi who will awaken as Chibiusa's bodyguards when she takes on the role of Sailor Moon. They represent four of the asteroids in the Solar Systems astroid belt that were at one point in time classified as Planets. Their names are Sailor Juno, Sailor Ceres, Sailor Vesta, and Sailor Pallas.
They were prematurely awakened in the Dream arc of the manga by the Dark Moon Circus and recruited as the villianesses JunJun, CereCere, VesVes, and PallaPalla (the Amazon Quartet). After the Dark Moon was defeated in the manga their true senshi forms were revealed. In the anime the Amazon Quartet appear in the SuperS season but are not senshi.