Quindecim

Quindecim is a bar tended by Decim and Black-Haired Woman. Its name is Latin for 15. It is on the fifteenth floor.

Appearance
Quindecim appears to be modeled as a modern European bar. At the counter, it is lavishly decorated in a Grecian/Roman design. It consists of several shelves stocked with fine wine and alcohol. In the center is a beautiful centerpiece with a circular design that also doubles as the game board that decides what game the customers will play. The shelves will move to reveal a secret room that features a room used solely to store Decim's mannequins which are used to scare customers into thinking they will be killed if they do not participate in the game. It is revealed that these are the dummies of past guests. Below the shelves are drawers and an oven. The bar itself is rather dark and spacious with not much lighting and uses dark colors such as purple and red. There are tanks filled with water and fish. It features dark purple couches, a piano with a mannequin, and a tall elegant chandelier. The tile floor featured red tiles that serve as a "path" for the customers to follow. In order to access the bar, the customers or visitors use elevators (there are two) that lead to a hallway that features two bathrooms on the side (male or female) with interiors that are also decorated in dark purple and match the rest of the bar and lead to the bar. When a customer chooses the game, the floor will open to reveal the game they will play. There also seems to be an extra room that holds an upper lever where a person can watch from below, similar to the seating in an opera house as there are several mannequins sitting in fancy clothing appearing as if they are watching in opera. There is also a back to the bar that features rooms presumably for living. While Chiyuki's bedroom has been seen, Decim's has yet to be revealed.

Trivia

 * It is likely the arbiters Quin and Decim were named so for working on the fifteenth floor.