Regarded as the 14th and final heir to the Kōga-ryū Wada-ha Ninjutsu tradition, he was highly respected by his peers and a core member of Japan's classical martial arts community.

Notable students include Motokatsu Inoue, Mabuni Kenwa, Saito Satoshi, Fujitani Masatoshi, actor Tomisaburo Wakayama and Manzo Iwata, who became heir to some of his styles.

Seiko Fujita published Zukai Torinawajutsu showing hundreds of Hojōjutsu ties from many different schools, and several other texts on ninjutsu and martial arts.

He died of cirrhosis of the liver at about the age of 68 and likely suffered from hereditary angioedema (which can preclude the practice of martial arts, although Fujita may have demonstrated the ability to overcome some disease symptoms).

[3] His vast collection of books, scrolls and historical documents, the Fujita Seiko Bunko, is housed at the Odawara Library in Kanagawa Prefecture.