Miyamoto Musashi's most famous duel was against Sasaki Kojiro, his greatest and most skilled opponent. It was said that Sasaki fought many duels against Japan's best and never lost.
Sasaki developed a very effective Kenjutsu style based on the movement of a swallow's tail in flight. Unlike other samurai who used the traditional 'katana', Sasaki used a 'no-dachi', which was a very long two-handed sword. Despite the sword's length and weight, Kojiro's strikes with the weapon were unusually quick and precise. Kojiro was Lord Hosokawa Tadaoki's private kenjutsu instructor.
The two greatest swordsmen agreed to fight, and the duel took place on April 13, 1612 on Ganryu Island, located off the coast of the Bizen Province. The duel was set for early the next morning. On the day of the fight, Sasaki Kojiro and the officials serving as witnesses waited for Musashi for hours. His absence lead to the rumor that Musashi had run away in fear of his life because he was so terrified of Sasaki Kojiro's technique. Nothing was further from the truth.
Miyamoto Musashi was transported to Ganryu Island on boat by a local fisherman, and, as part of his strategy, he arrived late for the duel once again, thus disturbing his opponent's inner state. During the short trip, he sculpted a wooden sword which he used for the duel against Sasaki Kojiro.
When the boat finally arrived, Sasaki and the officials were standing on the beach waiting for Musashi. Extremely irritated and blinded by rage, Sasaki Kojiro drew his katana and threw away his scabbard. Musashi saw this gesture and said to his enemy, “If you have no more use for your sheath, you are already dead."
"It was at this point that Musashi attained
satori or spiritual awakening."
The dual began, and both men were on guard with respect for the other's ability. One mistake, and it would all be over. Musashi provoked Kojiro into making the first attack, and then countered quickly, breaking Kojiro's left ribs and puncturing his lungs, thus killing him.
Before running back to his boat, Musashi bowed to his downed opponent and the officials, realizing with sadness that one of the greatest swordsmen ever had just died. It was at this point that Musashi attained satori or spiritual awakening. From this moment on he renounced ever doing lethal duels.