Casshern awakens to find his world reduced to a corrosive wasteland. Lost in a future he does not recognize, he struggles to stay a step ahead of those who wish death upon him.
An encounter with the mysterious Lyuze offers Casshern a fragmented glimpse of his role in the Ruin. After stumbling upon a community of “dying” robots, he discovers the true depth of his infamy.
Akoes warns Casshern against a life spent running from the past. When Friender arrives to make the assassin pay for his sins, Casshern chooses a path that could terminate his own existence.
Beautiful Sophita is feared by robots who wish to live as long as their decaying bodies will allow. Fighting makes her feel alive, and Casshern’s special abilities make him a foe she could fight forever.
Lyuze reveals her reason for hating Casshern, who offers her a chance for revenge. When robotic bandits attack Ringo and Ohji, Casshern comes to their rescue, but his rampage terrifies those he hopes to save.
Casshern desperately seeks to unravel the mystery of his dark past. An altercation with Dio, his robotic mirror image, could provide answers to his many questions - or at least get him killed.
Lizbell is obsessed with building a giant bell to remind the world that beauty still exists. She scavenges parts from decaying robots, and Casshern’s pristine body could be the final piece of the puzzle.
A rescue attempt by Casshern lands him at the bottom of a graveyard for abandoned robots. While a sweet - but simple - young girl tends to his wounds, Casshern hears whispers that Luna may still be alive.
Dio’s mission to assemble a robot army is interrupted by the appearance of Dune, a formidable warrior who was once Luna’s bodyguard. Elsewhere, Casshern continues his search for Luna.
Friender receives help from a caravan of robots and humans after Casshern is trapped beneath falling debris. But when the canine’s new allies unearth the man who killed Luna, the situation takes a violent turn.
The search for Luna leads Casshern and Friender to Margo, an artist who refuses to let the Ruin destroy his spirit. Casshern finds inspiration in the artist’s vision, but there are those who would rather see him dead.
Dying robots far and wide herald the saving grace of Luna. Meanwhile, Lyuze is disturbed to notice that Ringo has begun to rust, and Casshern is confronted by the monster who ordered him to Ruin the world.
Ringo’s attempt to comfort Casshern leads her into a deadly trap. Ohji is quick to come to her rescue, but for them both to escape alive, Casshern must fight Dio as Braiking Boss looks on.
Despite his ragged condition, Dune continues his search for Luna. The robot once feared as the “God of Death” is ceaseless in his quest, but a rematch with Casshern puts his dream of a reunion on hold.
During a rare moment of peace, Casshern presses Ohji for the story of Ringo’s origins. Elsewhere, Dio and Leda cross paths with two deadly robots that were once the strongest of their kind.
Casshern and his traveling companions befriend three children claiming to be descendents of Luna. When the youngsters are attacked by Leda, Casshern risks his own life to protect them.
Lyuze’s psyche is bombarded by a labyrinthine barrage of illusions. Her nightmarish journey leads to a shocking discovery about her true feelings for Casshern.
Casshern, Lyuze, and Ringo finally reach Luna’s castle, where they find countless robots hoping to be spared from the Ruin. Dune is among their ranks, but Luna’s treatment of her former protector is shocking.
Luna asks Casshern to serve as her new guardian; Lyuze and Ringo lose faith in the promise of salvation; and Ohji returns with disturbing revelations about the Sun Who Was Called Moon.
Leda tries to convince Dio to accept Luna’s healing, but eternal life is no longer his obsession. Dio now lives only to fight Casshern - even if their battle ends in his own destruction.
Casshern and Dio continue their epic final battle. Although only one will survive, they’ve embraced the chilling reality that fighting is the sole purpose of their tragic existence.
Casshern and his friends enjoy the peace of their new lives until the Ruin destroys their happiness. Driven by grief, Casshern sets out to settle the score with Braiking Boss - and issue a warning to Luna.
