No.6 is known as the perfect city.
No.6 is one of many Utopian cities built after the apocalypse to offer a better life to its inhabitants. During the last war, the human race destroyed half of the earth's habitable land so all military force was banned. From 6 remaining regions, 6 city-states were formed; No 6. was one of them. There are organized paths and ways of doing things. Breaking any of the strict rules can result in different punishments, from being stripped of citizen privileges to being send to the correctional facility. The city design can be compared to the Venus Project, which is a futuristic city planned to provide the most sustainable and optimal living conditions for humans. No.6 appears to have a better environment than its surrounding area and an abundance of greenery, it is also the only city-state that requires its citizens to wear ID bracelets. There is no such thing as despair in No.6, its citizens live a life with no restriction and luxury, as long as they are obedient and contribute to the system.
An ideal society by appearances, No.6 molds its inhabitants into obedient and submissive subjects. The children, who are considered the pillars of the future, pledge their loyalty to No. 6. They are to work hard for a better life, but are told never to voice suspicions about anything the city does. Doing so is a punishable offense.