No.6

Synopsis

By harboring a fugitive, Shion is stripped of his elite citizen privileges and forced to live in the suburbs with his mother. Four years later, while working at the waste disposal center, he learns of a mysterious parasite that makes people grow old and die in seconds. Having questioned the authority of the city once again, Shion is arrested, but is rescued by Nezumi while being transferred to prison. After the duo escape from the city's limits, Nezumi shows Shion what really lies beyond the walls of No. 6.

(Source: No.6 Wiki)