: The primary antagonist, a mysterious serial killer leading a group to take down the Japanese Association of Assassins (JAA) . Serialization and Adaptation
: Sakamoto’s supportive but firm wife, whose disapproval of his old lifestyle is the primary reason he remains retired. : The primary antagonist, a mysterious serial killer
: A highly skilled martial artist and daughter of a triad family whom Sakamoto and Shin rescue. : The primary antagonist