Probably "In the Prison".

Created by cartoonist Hanawa Kazuichi, it is based on real experience. The author was sentenced to 3 years in prison for illegally possessing modified guns.

The manga later almost won the Tezuka Osamu Cultural Award, but the author refused to accept the award.

It talks about a lot of "prison delicacies" and the daily prison life like dormitory life, "everything is available except freedom"... It is adapted from the TV series "In the Prison" of the same name, starring "The Lonely Gourmet" Yutaka Matsushige.

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