Ono Tadaaki

Ono Tadaaki was born in 1565 in Miko-gami, Awa Province (in present-day Minamibōsō, Chiba Prefecture). Known in his youth as Mikogami Tenzen, he set his heart on the way of the sword early on and became a leading disciple of Itō Ittōsai Kagehisa, founder of the Ittō-ryū school. Ittōsai was a legendary swordsman said to have never lost a bout in his life, and under his rigorous tutelage Tadaaki mastered exceptional swordsmanship.

In the famous duel at Koganehara, held to determine the orthodox successor of Ittō-ryū, Tadaaki is said to have defeated his fellow disciple Ono Zenki and received Ittōsai's certification as heir to the school's true lineage. He was thereafter recruited into the service of Tokugawa Ieyasu and changed his surname from Mikogami to Ono. He reportedly took part in the Battle of Sekigahara and the Siege of Osaka, demonstrating his ability not only in swordsmanship but in actual combat.

Tadaaki was eventually appointed sword instructor to the Tokugawa shogunal house, earning the honor of teaching Ittō-ryū to the second shogun, Tokugawa Hidetada. His lineage became established as the 'Ono-ha Ittō-ryū,' which grew into one of the mainstream schools of shogunate swordsmanship throughout the Edo period and influenced numerous later schools, including Hokushin Ittō-ryū. He died in 1628 at the age of 64. The technique and spirit he perfected in swordsmanship left a lasting mark on later sword culture, and he remains an important figure in the history of Japanese kendō.