Sword of the Stranger

A young boy named Kotaro escapes unknown pursuers along with his dog Tobimaru. A monk named Shouan directs him to seek help at the Mangaku Temple in the Akaike Province. The journey marks the start of his perilous quest during the Sengoku period.

Ming Chinese warriors under Bai-Luan are escorted by Akaike soldiers to build a large altar on Akaike land in exchange for gold. The group is ambushed by bandits, but is massacred by Luo-Lang, the Ming's expert Western swordsman. The day introduces the deadly stakes surrounding the altar project.

Kotaro and the wandering swordsman Nanashi shelter in an abandoned temple. A Ming warrior attacks; Nanashi kills him, but Tobimaru is wounded by a poisonous dagger. This encounter forces Kotaro to hire Nanashi as his bodyguard.

Nanashi takes Tobimaru to a doctor for treatment of the wound. Kotaro then hires Nanashi to protect him from the mounting danger surrounding the boy. The bond between the two new protectors grows as threats loom.

A Ming warrior Tu-Si is captured by Akaike soldiers and tortured to reveal the reason for the altar. He discloses that the Ming Emperor seeks an immortality elixir called Xian Medicine and that Kotaro's blood could serve as the essential ingredient. Lord Akaike then shifts his plan to capture the boy for ransom.

Nanashi shares sparse details about his past, including that he is a shipwreck survivor with red hair who dyes it black to blend in. He leaves Kotaro in Shoaun's care at the Mangaku Temple to protect him, but the monks later surrender the boy to the Ming to save their own lives. When Akaike soldiers arrive, Nanashi returns, only to find the Ming have already departed with Kotaro.

Bai-Luan learns of Akaike's betrayal and is captured by the Ming, who use him as a human shield at the fortress containing the altar. The Ming aim to await the prophesied time for Kotaro's blood sacrifice with the boy in their grasp. Itadori, an ambitious Akaike general, leads a rescue mission but has his own ambitions.

Itadori leads a small battalion to rescue Lord Akaike but shifts gears, deciding to kill him and seize command for himself. The power struggle destabilizes the rescue operation. The assault proceeds with the Ming and Akaike forces clashing around the fortress.

A brutal battle erupts at the fortress as troops clash to control the altar. Many Ming and Akaike soldiers are killed in the fighting, including Itadori who dies during the assault. The outcome shifts the balance of power surrounding Kotaro and the ritual.

Nanashi arrives at the fortress just as Kotaro is about to be sacrificed and is knocked unconscious briefly. He recalls a vow to never unsheathe his sword after a past order to execute two children, and then fights his way to the altar to save Kotaro.

Bai-Luan attempts to shoot Nanashi, but Luo-Lang kills his master so that he can challenge Nanashi to a final duel. The two swordsmen engage in a tremendous fight, their clash destroying much of the surrounding structure.

Despite severe injuries, Nanashi defeats Luo-Lang, who dies slowly and is surprised by his defeat. The final duel resolves who will protect Kotaro and the future path of the boy.

The next morning, Kotaro rides off on horseback with Tobimaru, carrying a badly wounded Nanashi. They talk about starting a new life together, leaving behind the danger of the altar and the prophecy.