[4] Around 1640, Musashi intended to pass on his art to three successors from among his thousand students; specifically, to Terao Magonojo, his younger brother Kyumanosuke and to Furuhashi Sozaemon.
[5] Magonojo died in 1645 and yielded the role of successor to his younger brother Kyumanosuke[5] who had received the Hyoho San-jugo from Musashi.
It was Kyumanosuke who transmitted this document to his students with seven added instructions called the Hyoho shiji ni kajo.
Succession in the Hyoho Niten Ichi-ryū (the name given by Musashi towards the end of his life) does not follow a hereditary pattern.
It is attested to by the bestowing of two artifacts: a scroll on which is written the name of the techniques and the approach to them that must be transmitted if the school is to be perpetuated truly,[3] and a wooden sword that Musashi made himself, with which he trained and used as a walking stick during the last years of his life,[3] today in possession of the city of Usa's Shinto Shrine.
He moved back to Japan but left Musashi's scroll and wooden sword handed down for safe keeping due to Japan's ban on combat sports that facilitated “the removal and exclusion from public life of militaristic and ultra nationalistic persons.” Aoki's student returned the relic in 1958.
[5] In 1968, Aoki named Kiyonaga Tadanao and Gosho Motoharu dual soke of the school.
Miyagawa Yasutaka established a line of Niten Ichi-ryū that continues to practice and thrive in the Kansai region of Japan.