Saizō Atō (亜東 才蔵 Atō Saizō ) is Seleção No. 12. A powerful businessman who helped build postwar Japan. He is later revealed to be Mr. Outside (ミスター・アウトサイド Misutā Autosaido ).
An unseen and mysterious character, he chooses eleven Japanese citizens as Seleção and gives them the phones with their mission to bring stability to Japan in whatever manner they wish. However, he warns that he will send a "Supporter" to eliminate any Seleção who uses up their money before they can complete their mission, acts selfishly, idles for an extended period of time, or breaks his rules.
Akira Takizawa later realizes that "Ato Saizo" is a pun for the Japanese pronunciation of "Outside." A football enthusiast, Saizo's inspiration for the Seleção name came from the Portuguese word for selection and the common nickname of Brazil's national team. His true identity is not revealed until Paradise Lost, where he is an elderly man who has posed as a simple cab driver. All of the Seleção were passengers in his cab at some point, where he asked them how they would spend 10 billion yen, with the exception of Takizawa (who had met Atō Saizō when he stopped beside the taxi on a bike). After the events of the Paradise Lost film, Saizo declares all of the Seleção are winners and has their memories erased to free them from the game. Takizawa manages to keep his memories, and tracks down Saizo so that they can work together to improve Japan. Saizo also has four female helpers who call him "Grandpa" and assist him with the game.
|Eden of the East|
|Eden of the East||Kazuomi Hirasawa • Yutaka Itazu • Saki Morimi • Satoshi Ōsugi • Haruo Kasuga • Mikuru Katsuhara • Sis|
|Seleção|| Juiz • Mr. Outside • Ato's granddaughters |
Players:  Daiju Mononobe •  Jintarō Tsuji •  Toshiko Kitabayashi •  Yūsei Kondō •  Hajime Hiura •  Taishi Naomoto •  •  •  Akira Takizawa •  Ryō Yūki •  Kuroha Diana Shiratori •  Saizō Atō
|Others||AKX20000 • Angelika • Chigusa Iinuma • Seijiro Iinuma • Aya Iwashita • Asako Morimi • Asako's baby • Ryosuke Morimi • Misae Naomoto|
|Characters in bold are the main characters|