Main characters ; / : :A secretive young man with a bright mind and calm demeanor who moves to Tokyo and attends high school alongside Twelve under the name "Arata Kokonoe". He is one of the masterminds behind Sphinx. He and Twelve are survivors of a secret experiment by the Rising Peace Academy to develop 26 highly intelligent orphaned children into human weapons. ; / : :An apparently childish young man who is the second member of Sphinx. He is kind and caring, and befriends the lonely schoolgirl, Lisa. He uses the civilian identity of "Tōji Hisami" and is skilled at operating vehicles like motorbikes and snowmobiles. Twelve has
synesthesia; that allows him to see sound as color. ; : :A high school girl with a problematic life both at home and school. She is befriended by Nine and Twelve who save her from bullies at her school and she becomes caught up in their plans. ; : :A detective of the
Tokyo Metropolitan Police Department who used to be an ace of the police force's investigations division, but was demoted to its records division after continuing an unauthorized investigation. He is highly intelligent and is called back into the force to investigate the terrorist group Sphinx. ; : :She is the third survivor of the Rising Peace Academy experiment, highly competitive and has a love-hate relationship with Nine because of his talent. She becomes an American
FBI operative who travels to Japan as part of her duties with
NEST to lend support to the terrorist attack investigations. Her obsession with Nine exposes her willingness to endanger, or even kill, innocent people to get close to Nine and Twelve.
Supporting characters ; : :The chief of the
Tokyo Metropolitan Police Department station, who heads the investigation into Nine and Twelve's bomb threats. ; : :A passionate, young police officer who collaborates with Shibazaki even after he is suspended. ; : ; : ; : :Shibazaki's co-worker from the records division who helps him solve Sphinx's riddles. ; : :The head of Shibazaki's team and later the chief. ; : :A scientist working to identify the bombing techniques used by Sphinx. ; : ; : ;
Clarence : :Five's partner and an
FBI agent. ; : :Lisa's mother, who is highly paranoid and extremely possessive of Lisa due to her husband leaving the family home. ; : :Shibazaki's daughter who is studying particles. ;Mamiya : :The creator of the Athena Project. ==Release==