Mori no Asagao(2004)

As a new prison guard assigned to death row, Oikawa Naoki faces condemned criminals every day, trying not to make a connection with men he knows are doomed to die. In the course of his duties, he strikes up a unlikely friendship with inmate Mitsuru Watase, a man sentenced to die for the revenge murder of the man who killed his parents, and slowly begins to wonder about the necessity of the death penalty and the meanings of concepts like repentance and forgiveness. Based on close and careful research, this thought provoking work tackles the serious theme of the “capital punishment system” head-on, from the view of both those who execute others and those who are executed.

(Source: JManga)