Deadman Wonderland(2007)

Deadman Wonderland

The inmates of this insane penitentiary fight for survival every day to provide entertainment for the masses, and terrifying secrets lurk in the shadows. Ganta is determined to survive Deadman Wonderland and clear his name, but the price may be his soul…

(Source: VIZ Media)

Note: Volume 12 contains 6 short side stories, which counts as 1 whole chapter.