When the once powerful Imagawa clan fell to the conquests of Oda Nobunaga, Jushin decided to dedicate his life to martial arts training.
[3] He left the castle for the Atago Mountains where he underwent intense physical and spiritual training.
The result of that training became known as Sekiguchi Shin Shin-ryū, and rumors of the wanderer and of his art rang throughout the country.
[4] During World War II many of the ryū's documents containing history and techniques were lost in fires from Allied bombing.
After a 15-year pause in training, Yoshitaro, the 12th Sōke, with the help of head student Fujimura Shigeru restored the art and passed it on to the present soke, 13th generation, Sekiguchi Yoshio.