The brilliant lawyer Joe Akizuki's life shatters when his wife Mari is raped by his closest friend and driven to suicide. Consumed by a thirst for vengeance, Joe takes on the friend as a client, secures a reduced sentence, and then personally executes him with a gun. A game of Russian roulette leaves Joe alive, and he emerges as a new man: a shadowy international attorney known only as J, the Outlawyer, now wanted by Interpol. Adopting the alias and operating beyond the reach of any single nation's law, J dedicates himself to taking on only the most impossible cases—wrongful convictions, framed innocents, and conspiracies that the legal system cannot or will not touch.

From his first case, The Man of Extraterritoriality, J travels the world, navigating a web of corruption, crime, and international intrigue. Each arc presents a client trapped by injustice: a man framed for murder, a woman caught in a mind-control plot, a brotherhood fractured by betrayal, and a conspiracy that reaches the highest levels of power. Along the way, J confronts figures from his own past, including the surviving members of the cabal that destroyed his wife, and uncovers a deeper truth behind her death. The narrative weaves action, courtroom drama, and moral ambiguity as J balances his role as a defender of the falsely accused with his own unresolved vendetta. The series culminates in a final courtroom confrontation where Joe Akizuki himself must stand trial, forcing him to reconcile the man he was with the outlaw he has become.