No.6 is a tV series anime that premiered in summer 2011, produced by bones.

About the production: the story comes from a other, there are 11 episodes of about 23 minutes and its current status is "finished".

Its main genres are action, drama, psychological and sci-fi, with themes such as Conspiracy, Male Protagonist, Time Skip and Class Struggle.

On AniList, No.6 has an average score of 73%, a good score, and appears on 104,496 users' lists.

In a near future world, after the last great war, most of mankind lives in a handful of city states. There, for the privileged elite, life should be perfect. But for young Shion, the only thing perfect has been the nightmare his life has become since letting a strange boy called Rat spend the night in his apartment. Banished to the outskirts of the city and stripped of all privileges for helping the mysterious stranger who has since disappeared, Shion now finds himself in even worse danger as his inquiry into a new series of mysterious deaths results in his being arrested on suspicion of murder! But even as Shion is being sent to the city's Correctional Institute, the long-missing Rat reappears to rescue him! Now on the run, the two young men have only one chance at survival: uncover the mysterious secrets that lie at the sinister heart of No. 6! (Source: RightStuf)

Official synopsis from AniList.