In a futuristic yet feudal Japan, it is said that the one who wields the Number 1 headband is the fiercest fighter in the world and shall possess god-like powers. The only way to obtain the Number 1 headband is to challenge and defeat the current wearer in combat. However, only the Number 2 can challenge the Number 1 whereas anyone can challenge the Number 2. Thus, whoever wears the Number 2 will face a constant struggle. In the mountains, Justice, the owner of the Number 2 headband, fights with the owner of the Number 1 headband Rokutaro (Afro’s father), and kills him by beheading him and claims the Number 1. Afro witnesses the fight and vows revenge against Justice who tells him to seek him out when he is “ready to face a god.”
Years later, Afro is the current Number 2 and a master swordsman who travels his way to the mountaintop keep where Justice awaits, he recalls his journey from a frightened young boy to a master samurai. Along the way, Afro defeats and kills the “Empty Seven Clan”, and their various agents, robots and assassins, including a robotic Afro. He also confronts his vengeful childhood friend Jinno (who survived in their past). The flashback reveals that Afro’s childhood samurai teacher called the Sword Master wears the Number 2 headband, before Afro meets and confronts him. They are both attacked and killed by assassins, leaving Afro, Jinno, Otsuru (Okiku) and their master survived. Despite Jinno’s plea, Afro kills their master and claims the Number 2 headband. Blaming Afro for revenge, Jinno falls from the cliff. Back in the present day, Afro discovers that there are other headbands in existence, ranging to an unspecified higher number and sees that the corpses of those who wore them are skewered throughout the room, where he confronts and defeats Justice.
After taking the Number 1 headband and seeing all headbands disappear, Afro returns and lives in the mountains, and confronts Jinno who is adorned with every headbands in existence for revenge.