Five Numbers!

Four men are assigned to the prison: Juugo, a man who attempted to break out of prison and ended up extending his jail time; Uno, a man who likes to gamble with women; Rokku, a man who likes to get into fights; and Nico, a man who likes anime.

The gang is back to their usual antics and things have returned to normal in Nanba prison. However, the status quo is upset when a former guard turned inmate enacts a plan of his own.

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!

The snowy, ice-covered planet Coldfoot is home to a precious energy-rich ore called “Sig.” On the surface, the planet seems to be a crime-free utopia, but in reality prisoners are used for back-breaking Sig mining. Jim, a young prison guard, rushes to the site of a sudden mining accident to find a mysterious creature attacking the humans.