claims to be the last, and only, heir to authentic Ninjutsu . He says he is the 21st head of the Koga Ban Family (Iga and Koga Ninjutsu) and is the honorary director of the Iga-ryu Ninja Museum.
- Wingspan: Culture-Society-People in Japan, Where Have All the Ninja Gone? by Thomas Dillon (September, 2007 No.459)
- Historical group image editorial staff compilation by Kuroi Hiroshi optical work (ISBN 978-4-05-604814-8)
- The Last of the Ninja by Thomas Dillon