TV-Series
Description
Musashi Miyamoto is presented as the legendary Japanese swordsman from the early Edo period, who, contrary to historical records that state he died in 1645, is still alive and over four hundred years old. He makes his home on a cliff at Mount Tengu, where for centuries he served as the guardian of the Raijin-ken, a legendary sword imbued with the power of the thunder god. In his youth, he was a tall and handsome man, but over the centuries his appearance has changed dramatically. He is now a diminutive and weathered old man, easily recognized by his long, antenna-like eyebrows. His physical transformation is so complete that former rivals and pupils, such as Kojiro Sasaki and Jubei Yagyu, are unable to recognize him when they are revived in the present day.

Despite his advanced age and frail-looking frame, which is prone to back spasms and has a fragile hip, Musashi's skill with a sword remains extraordinary. Having won over sixty duels in his lifetime, his reflexes are still incredibly sharp, and he is a master of the Niten Ichi-ryuu, also known as the Two Heavens as One Style or the two-sword style, a technique for which the historical Musashi is famous. He acts as a more responsible and less lenient master to the young protagonist Yaiba Kurogane compared to Yaiba's own father. However, Musashi is not without his own flaws, as he shares Yaiba's gluttonous and lecherous tendencies, often behaving like a thievish and perverted old man. He is known for his distinctive and trademark laugh, which sounds like Hyo~hyohyohyo.

Musashi's primary role in the story is as a mentor and teacher to Yaiba. After Yaiba proves himself worthy by pulling the Raijin-ken from its stone, Musashi takes the young samurai under his wing, training him to properly wield the sword's power and to become a true samurai. He becomes a central figure in Yaiba's group, often acting as the brains of the operation, using his centuries of experience and tactical brilliance to guide the younger heroes in their battles against formidable foes like the demon Takeshi Onimaru and the celestial beast Yamata no Orochi. His deep knowledge of history also proves invaluable, as he is personally acquainted with many of the historical and legendary figures the team encounters.

The character's long life and personal history are central to the plot. His most famous historical duel, against his great rival Kojiro Sasaki on Ganryu Island, is revisited when Yaiba travels back in time. In a twist of fate, Yaiba is forced to disguise himself as Musashi to win the duel and prevent a time paradox that would erase his own existence. This event had a profound effect on the real Musashi, who witnessed it and adopted the younger swordsman's determination to win and survive at all costs, a new mindset that he credits for his own four-hundred-year survival. Despite his cranky exterior and questionable behavior, Musashi is haunted by a sense of guilt over Kojiro's death and remains dedicated to upholding the ideals of the samurai, even in a strange, modern world. By the end of the story, his adventurous spirit remains undimmed, as he is last seen on Mars, having gotten himself into trouble while trying to steal a hoard of diamonds.