In Japan after the end of the Second World War, an American soldier reaches behind the bars where he spends a good deal of time, and there he makes his friend an influential member of the terrible Japanese mafia organization, Yakuza. He uses his levers to help the American get out of jail faster, and as gratitude for his favor he enters his organization and takes a blood oath by which he will be willing to do some of the most terrible affairs for the good of the organization. His ascension to the Yakuza ranks is a fulminating one and immediately attracts the envy of older members who look at him with suspicion and distrust.