- 1 Season
No. 6 is a Japanese anime, or animation, geared towards teens or adults. It takes place in the distant future, when the world has been divided into six habitable zones. The strictest zone is No. 6. No. 6 claims to be a kind of paradise, but restricts what its citizens can do, read and watch. Dissenters are often sent to a rehabilitation facility, and are sometimes never heard from again. When he's twelve years old, one of the main characters, Sion, begins to question his place in society. His world is turned even more upside down when another young boy, Nezumi, shows up on his balcony. Nezumi is on the run from the No. 6 authorities, and seeks refuge with Sion. Although he knows it is against the rules, Sion immediately decides to befriend and help Nezumi. After just one night, Nezumi continues on his way, eventually escaping outside the walls of No. 6. However, Sion's perfect life has suddenly been destroyed. For helping a fugitive, Sion's perfect life and future are stripped away. Instead of becoming the scientist he was supposed to be, Sion ends up working a menial job when he's just sixteen years old. Sion feels all right about the ways things have turned out, though. He realizes that he may need to begin questioning the society he lives in. As a deadly disease begins spreading through No. 6, Sion becomes more and more suspicious about the government. When he is captured by No. 6 officials and taken in for questioning, he believes that he will never return. However, Nezumi quickly comes to his rescue, and takes Sion outside the walls of No. 6. The two boys quickly return to the close friendship they formed when they were twelve years old. Although Nezumi wants to destroy No. 6, and Sion wants to save it, the two boys begin working together. They are both searching for a way to break free of society's restrictions.