The Chiester Sisters Imperial Guard Corps, or known simply as the Chiester Sisters, are a group of villainesses from Umineko no Naku Koro ni. They are furniture resembling bunny girls that can be summoned by ones with substantial summoning skill. Their main weapon is a bow of light that shoots golden arrows which can kill any target they choose instantly, the only exceptions being Battler Ushiromiya or the Territory Lord. Dlanor A. Knox implies that she has begun investigating them and that their vessels are the weapons used in crime which are the four Winchester guns. One of these four guns is defective and shoots low, namely, Chiester 556's vessel. In Twilight of the Golden Witch, it is confirmed that their original vessels were Maria's ceramic bunnies, one of which was destroyed by Rosa Ushiromiya.
"The Chiesters are bunny-girl servants summoned by Beatrice. It is said that there is no escape from the Siestas' attacks, and they can even locate and bring back a corpse. They have red eyes, bunny ears, and elaborate military-styled outfits. It is hinted that they are connected to Maria's three (originally four) rabbit toys."
- The Chiester Sisters are revealed to be a large force in Dawn of the Golden Witch. Chiester 410 names two others, Chiester 127 and Chiester 20. Chiester 127 is said to be able to pulverize a human target at 2 kilometers, while Chiester 20 has a fire rate of 6,000 rounds per minute. Since all the other Chiester sisters are named after gun rounds, Chiester 127 most likely references to the 5-inch deck gun which has a 127mm wide shell and a range of well over 2 km. Chiester 20 likely references to the M61 Vulcan Gatling Gun which fires a 20mm round and also has a fire rate of 6,000 rounds per minute.
- Even though their firing codes are written in Greek, the banners they have on their left arm resemble the flag for Iceland.
- The name Chiester is a corruption of the word Winchester, a series of guns that Kinzo Ushiromiya is shown to own.