Musashi challenged Yoshioka Seijūrō, master of the Yoshioka School, to a duel. Seijūrō accepted, and they agreed to a duel outside Rendaiji in Rakuhoku, in the northern part of Kyoto on 8 March 1604. Musashi arrived late, greatly irritating Seijūrō. They faced off, and Musashi struck a single blow, per their agreement. This blow struck Seijūrō on the left shoulder, knocking him out, and crippling his left arm. He apparently passed on the headship of the school to his equally accomplished brother, Yoshioka Denshichirō, who promptly challenged Musashi for revenge. The duel took place in Kyoto outside a temple, Sanjūsangen-dō. Denshichirō wielded a staff reinforced with steel rings (or possibly with a ball-and-chain attached), while Musashi arrived late a second time. Musashi disarmed Denshichirō and defeated him. This second victory outraged the Yoshioka family, whose head was now the 12-year-old Yoshioka Matashichiro. They assembled a force of archers, musketeers and swordsmen, and challenged Musashi to a duel outside Kyoto, near Ichijō-ji Temple. Musashi broke his previous habit of arriving late, and came to the temple hours early. Hidden, Musashi assaulted the force, killing Matashichiro, and escaping while being attacked by dozens of his victim's supporters. To escape and fight off his opponents he was forced to draw his second sword and defend himself with a sword in each hand. This was the beginning of his niten'ichi sword style. With the death of Matashichiro, this branch of the Yoshioka School was destroyed.