Miyamoto Musashi or Shinmen Takezo (his real name), only at a very young age, embarked on a journey to become the strongest samurai only after being exiled from his own village. Musashi is the son of a samurai family, who's father is one of the most renown samurai across the nation. One of the foremost reason that drives Musashi to excel in sword-fighting, is his desire to overcome his father for all the harsh treatment given during his childhood and Musashi's incapability to rebel.
Musashi is unique in terms of his sword-skill for the unfamiliar movements and lack of style he use. This is due to the fact that he spent most of his entire time in the forest having been labeled as a demon child by his village for his demeaning and wicked nature. Frankly, the forest is his home and where his master resides.

Demon Eyes Kyo is said to have slaughtered a thousand men. Although his reputation actually belongs to Kyoshiro, he has certainly killed more than a thousand people himself. He is imprisoned in Kyoshiro's body and takes it over whenever Kyoshiro's life is threatened. Kyo fears no one and is quite arrogant and self-centered early in the manga. Throughout the story, he is looking for his real body, which was sealed somewhere by Kyoshiro. His ultimate goal is to become the strongest man in the world. His most distinguishing feature is his red eyes.