Traditionally the Hokushin Ittō-ryū Hyōhō educated children from a very young age in the arts of war, philosophy and etiquette, in order to raise them to become strong, responsible, disciplined and cultivated bushi (samurai). During the Edo period (1603-1868), the Hokushin Ittō-ryū brought out a couple of very young kenshi (swordsmen) who easily dominated adult master swordsmen, with decades of fighting experience from other martial traditions, in duels and on the battlefields of the Bakumatsu period (1853-1868).
One famous example was Umanosuke Kashio. He was born in 1838 in Awa and studied the Hokushin Ittō-ryū under the 1st sōke (head of the school) Chiba Sadakichi and the 2nd sōke Chiba Jutarō at the Chiba-Dōjō in Edo (nowadays Tōkyō). He was considered a genius swordsman who mastered the whole curriculum of the school in around three years, receiving the menkyo-kaiden (diploma of full mastery) around the age of sixteen in 1853-1854. It is said about him that he was especially skilled in the usage of the waza (technique) Hagunken (sword of the big dipper) during the shiai (duels) he fought. He was able to take on and successfully defeat master swordsmen of other ryūha (schools) who were much older and experienced than himself. This reputation earned him later the position of kenjutsu shihan (swordsmanship instructor) for a famous police force of the Tokugawa shogunate (the leading military government), teaching and educating much older swordsmen despite his very young age.
The age from which on children could enrol as students in the Hokushin Ittō-ryū, varied in each century and from sōke to sōke, but nowadays under the 7th sōke Ōtsuka Ryūnosuke, children from the age of ten or older are accepted to join and study the school.