This was likely Miyamoto Musashi’s first official duel
Yoshioka Seijuro was the head of the Yoshioka Dojo (a school specializing in swordsmanship) as well as the patriarch of the Yoshioka family.
It was decided that the fight would take place outside the Jobon-Rendai-ji Temple in Kyoto. They also decided that the duel would be non-lethal and would be fought with bokken (wooden swords) and that the winner would be declared by the first blow.
Miyamoto Musashi arrived hours late on the day of the fight. Musashi believed in a total warfare and eking out any potential advantage which included any psychological edge. Musashi eventually sauntered up to the temple, Seijuro was irritated and angry by this point, judging Musashi’s behavior to be completely irreverent and unacceptable.
The two opponents squared off against each other. Musashi apparently moved with incredible speed and stuck Seijuro hard in the shoulder with his Bokken knocking the man off his feet and breaking his left arm. Musashi was declared the winner.
Unable to accept with how quickly Musashi had bested him and reeling with a sense of dishonor, Yoshioka Seijuro retired from the Yoshioka school and became a monk.
Seijuro’s brother, Yoshioka Denshichiro, a talented swordsman, succeeded his brother to become the head of the Yoshioka Family.
He would later challenge Musashi to regain his family’s honor and avenge his brother’s defeat.