Masaaki Hatsumi (初見良昭 Hatsumi Masaaki) was born December 2, 1931. He graduated from Meiji University in Tokyo with a major in theater studies, and later opened his own chiropractic clinic in Noda city.

From his childhood he studied many martial arts, including judo and western boxing. But it was first when he met his teacher Toshitsugu Takamatsu that he found the arts that he wanted to dedicate his life to.

From Takamatsu he inherited the position of sōke (headmaster) of 9 ryū (schools of martial arts):

• Togakure-ryû Ninpô Taijutsu (戸隠流忍法体術)
• Gyokko-ryû Kosshijutsu (玉虎流骨指術)
• Kuki Shinden-ryû Happô Bikenjutsu (九鬼神伝流八法秘剣術)
• Kotô-ryû Koppôjutsu (虎倒流骨法術)
• Shinden Fudô-ryû Dakentaijutsu (神伝不動流打拳体術)
• Takagi Yôshin-ryû Jûtaijutsu (高木揚心流柔体術)
• Gikan-ryû Koppôjutsu (義鑑流骨法術)
• Gyokushin-ryû Ninpô (玉心流忍法)
• Kumogakure-ryû Ninpô (雲隠流忍法)

To facilitate the teaching of these schools he created the Bujinkan Dōjō organization that teaches the essence of all the schools. He is the grandmaster.

Some of his more well-known senior students include:

• Jack Hoban
• Stephen K. Hayes
• Fumio Manaka
• Bo Munthe
• Toshiro Nagato
• Isamu Shiraishi
• Shoto Tanemura