Nagai Jinsei, aka "Bare-Knuckles Jinsei". Born in a dumpster, raised in an orphanage, living as a yakuza, he is tough enough that he fights all his fights bare-handed, and is covered with countless knife and bullet scars from his battles. But his life changes when he saves the five-year-old Ayumi, daughter of the new police chief, Enjoji Masayoshi, and befriends their family. For the first time in his life, Jinsei feels like he found a family of his own, and decides to start his life over, but his past and his ties to the yakuza keep getting in the way.