As the cinematic curtain rises, a young samurai named Natoe finds himself navigating the desolate landscape of a besieged metropolis, ravaged by humanoid forces that have left destruction in their wake. With his sword slicing through the enemy lines, Natoe methodically dispatches the invaders, only to stumble upon the wounded Zex, a formidable foe who ultimately becomes a fleeting acquaintance. The villagers, desperately fleeing from the devastation, implore Natoe for assistance in defending their settlement against the impending humanoid onslaughts. Initially hesitant, he eventually declines their plea, choosing instead to continue his crusade against the remaining invaders.
The path of righteousness soon converges with that of Jodie, an old friend who rekindles memories of a bygone era. United once more, they embark on a dangerous journey to eradicate the remnants of the earlier invasion. Their quest culminates in an unexpected reunion with Kanbei, a seasoned warrior who recognizes the gravity of their situation and persuades Natoe to join forces with the villagers, warning him that alone he risks being overrun by the next wave of humanoid attacks.
However, Kanbei soon realizes that merely their combined strength is insufficient to protect the village. Thus, they set out to recruit five additional warriors, each boasting unique skills honed from years of combat. The odyssey leads Natoe to Totsuma, a cunning thief operating in the Scrapyard district, whom he bests and wins over to their cause. Kanbei then reveals the whereabouts of Rojie, a former comrade-in-arms who has since become the trusted bodyguard of Salla.
As Natoe and his companions venture into the heart of the city, they uncover Rojie's occupation and attempt to persuade him to join their ranks. Along the way, Natoe encounters Eight, an enigmatic warrior renowned for his stealth, before continuing his search for Rojie. After outmaneuvering and defeating Kyric, a ruthless drug lord, he skillfully navigates the treacherous underbelly of the city, ultimately tracking down Rojie.
With their team now assembled, Natoe reflects on Eight's mysterious exploits and suggests his inclusion. Together, they delve deeper into the city's labyrinthine sewers, only to inadvertently stumble upon the formidable White Fox, a humanoid adversary who tests their combat skills to the limit. This encounter culminates in a surprising meeting with the Man in White, a shadowy figure whose true intentions remain cloaked in mystery.
As events unfold, Jodie and Eight are revealed to be agents of the city, operating behind the scenes to untangle the web of intrigue. Natoe's timely intervention saves Eight from the clutches of the Man in White, leading him to join their ranks. With the stage set for the impending battle against the humanoids, Natoe and his companions unite, their bond forged through shared adversity and an unwavering commitment to protect the innocent.
As the trio comprising Natoe, Eight, and Rojie venture into the rural landscape, they are met with an unexpected convergence of city agents and the enigmatic Zwei. Upon their arrival at the village, Kanbei's instincts prove eerily prescient, as he and the samurai begin to sense a palpable unease among the inhabitants. Driven by curiosity, Natoe sets out to unravel the mystery surrounding Hinata's origins and the villagers' duplicitous intentions, ultimately revealing that the village is on the verge of a Humanoid assault.
Undeterred, Natoe ventures forth to find one final samurai ally capable of joining forces to repel the impending attack. His quest leads him to a desolate wilderness, where he confronts Zex and Fen, their faces a blend of hostility and anticipation. As Zex unleashes his colossal strength, Natoe plunges into an underground city known as the "Town of Warriors." Here, he encounters Ein, a Humanoid with the ability to harness magic for combat, and rescues Cue, a female humanoid stricken by amnesia, pledging to help her recover her lost memories in exchange for her assistance.
Natoe's time in the underground city is brief, as Jodie suddenly reappears, apologizing for her deception and providing cryptic instructions to find "the traitor" before vanishing again. Shortly afterward, he reunites with Eight, who has suffered brutal injuries but remains resolute, convinced of his ability to protect the child.
With renewed determination, Natoe, Cue, and Totsuma embark on a perilous mission to infiltrate Drei's fortress, the site where the Humanoid leader conducts twisted experiments on captured subjects. Along the way, Natoe uncovers an upgraded behemoth, the "Zex Beast," which he dispatches with precision. However, tragedy strikes as Totsuma falls victim to a trap, losing his life when the fortress collapses.
Returning to the village, the samurai take up defensive positions in preparation for the approaching Humanoid assault. Amidst the chaos, Eight makes the ultimate sacrifice, detonating one of the village's entrances to buy his comrades time to regroup and ready themselves for the battles that lie ahead.
Following the tumultuous conflict, Natoe faces off against Zwei and her three warriors, emerging triumphant as she retreats. In the aftermath, the village exhales a collective sigh of relief, but the enigmatic Man In White delivers a cryptic proclamation: the sacred child's services are no longer needed by the city, and Jodie has been taken by the humanoids. This revelation leads Natoe and Cue into an unlikely alliance against the final remnants of humanity at the ominous "Library of Avalon."
As they traverse this eerie facility, they confront a parade of nightmarish creatures known as "Guardians," while Cue begins to piece together fragments of her forgotten past. Just as she starts to reclaim her identity, Ein strikes, abducting her and prompting Natoe to battle an overwhelming horde of humanoids, including the formidable Ultimate Zex and ageless Fen. After besting these foes, Natoe finally confronts Ein, who becomes the god-like Almana through the absorption of Cue's essence. Seizing upon Almana's Achilles' heel—its ethereal wings—Natoe crafts a decisive attack that renders it vulnerable.
With Jodie safely restored to his side, Natoe returns to the village, only to confront the humanoid Zwei in a desperate bid for the sacred jewel's power. The ensuing duel takes place on a precarious bridge, leading to a heartbreaking moment when Jodie tumbles over the edge. Natoe manages to grasp her just in time, but his selfless act comes at a grave cost: he is stabbed in the back by Zwei. While he delivers a fatal blow to his opponent, the bridge collapses beneath them, condemning them both to the depths below, leaving only two samurai survivors.
In the wake of this tragedy, Kanbei solemnly reflects on an ancient prophecy: > "So again we are defeated. The farmers have won. Not us."
