In 16th-century Japan, Shinmen Takezou is a wild, rough young man in both appearance and behavior. His aggressive nature earns him the scorn and fear of his village, prompting him and his best friend, Matahachi Honiden, to flee in search of something greater than provincial life. They join the Toyotomi army, hoping for glory—but when the Toyotomi suffer a devastating defeat by the Tokugawa Clan at the Battle of Sekigahara, the two friends barely escape with their lives.
After they are separated, Shinmen returns home on a self-imposed mission to inform the Hon'iden family that Matahachi is alive. Instead, he finds himself a wanted criminal, framed for his friend's supposed murder due to his history of violence. Captured, he is tied to a tree and left to die. A wandering monk, the distinguished Takuan Soho, takes pity on the "devil child," secretly freeing Shinmen and giving him a new name to avoid pursuit by the authorities: Musashi Miyamoto.
Vagabond is a fictional retelling of the life of one of Japan's most famous swordsmen, the "Sword Saint" Musashi Miyamoto—his journey from a swordsman with no goal other than to become "Invincible Under the Heavens" to an enlightened warrior who gradually learns the value of close friends, self-reflection, and life itself.