Masaaki Hatsumi (良 昭 japonais, Hatsumi Masaaki [hatsɯmi masaːki], né le 2 décembre 1931 à Noda, au Japon, Hatsumi Yoshiaki) est depuis 1972 à la tête du dojo de Bujinkan.
At the age of seven, Hatsumi began to learn kendo from his father. Incidentally, he also trained aikido, judo and karate. At school, Hatsumi practiced gymnastics and boxing and was captain of the football team. He practiced dance, which helped him to learn Budō. In high school, he punched further and ran judo. He studied dramaturgy and drama.
He began to search for proper martial arts and practiced the fighting style ‘Kobujutsu Juhappan’ with a Japanese teacher named Ueno. After three years he had mastered the style and his teacher Ueno said that he could teach him nothing more. He advised Hatsumi to go to Nara and find a capable teacher. When Hatsumi was 25,  he met Takamatsu Toshitsugu, where he learned Taijutsu. From then on, Hatsumi traveled ten hours a week for over 15 years to Honshu. He left Noda on Friday night, stayed with his teacher over the weekend and trained with him. He left Takamatsu again on Sunday night and set out on the long way back to open his practice Monday morning.
Takamatsu gave Hatsumi a certificate in March 1958  that he was the 34th soke of the Togakure Ryu and thus his heir. At the age of 30, he married his wife Mariko.
Hatsumi decided because of the large extent of the nine traditions (Ryuha) not separated, but to exercise as a unit and called his dōjō “Bujinkan Dōjō”. On September 9, 1997, then the Bujinden (Hombu) Dōjō was opened. Until then, Hatsumi had alternately taught in the Dōjō his students.
The training under Hatsumi should have been very hard at first, but in 1988 he decided to adapt the Bujinkan to this aspect and mitigated the training. Since 1995, martial arts in Bujinkan Bujinkan Budo Taijutsu called.
Hatsumi claims to be the legitimate successor to the following nine Ryuha:
34. Soke – Togakure Ryu Ninpo
28. Sōke – Gyokko Ryu Koshijutsu
28. Sōke – Kukishinden Ryu Happo Hikenjutsu
21. Sōke – Gyokushin Ryu Ninpo
18th Sōke – Koto Ryu Koppojutsu
17. Sōke – Takagi Yohshin Ryu Jutaijutsu
16. Sōke – Shinden Fudo Ryu Dakentaijutsu
15. Sōke – Gikan Ryu Koppojutsu
14. Sōke – Kumogakure Ryu Ninpo
Most of these schools (Ryuha) are samurai schools. Three of the schools are the last ninja schools known to exist. See also Ninjutsu. Hatsumi has not named a successor yet.
Due to health problems (diabetes) and to take care of his wife, Hatsumi remains now only in Japan. He is still training in Bujinden (Honbu-Dōjō). He has received numerous military and public awards worldwide. He received two more doctoral degrees, one in philosophy and one in science. In 1986, he was awarded the Black Belt’s Instructor Of The Year Award. He is a scientist, impressionist painter, actor, musician, singer and author, has written countless columns in newspapers and magazines, has written many books on Ninjutsu and has published the Bujinkan magazine called “Sanmyaku”. He has made more than 25 videos and has participated in many films: “Shinobi no Mono”, 50 episodes of the popular children’s series “Jiraya” and “Suteki no Mama”.