For most of his adult life he was the only man fully trained in the art of Ninjutsu. Only after retiring to his village did he take on a single student, Dr. Hatsumi Yoshiaki. After 15 years of instruction Toshitsugu declared Dr. Hatsumi his only heir in the art of Ninjutsu.

Takamatsu Sensei's Shodo:

"nintai to wa kokoro o yashinai waza o hagemite suenagaku shinken ko so ma no ninja nari"
"the ninja's body is to nurture one's mind and to train the body to endure to the end.
One who can do this is a true ninja."

(From; the History of Kukishinden Ryu Bojutsu by Hatsumi Sensei)

The essence of all Martial Arts and military strategies is self protection and the prevention of
danger. Ninjutsu epitomizes the fullest concept of self-protection through martial training in that
the Ninja art deals with the protection of not only the physical body, but the mind and spirit as
well. The way of the Ninja is the way of enduring, surviving, and prevailing over all that would
destroy one.

More than merely delivering strikes and slashes, and deeper in significanse than the
simple out-witting of an enemy; Ninjutsu is the way off attaining that which we need while making the world a better place. The skill of the Ninja is the art of winning. In the beginning study of any combative art, proper
motivation is crucial. Without the proper frame of mind, continous exposure to fighting
techniques can lead to ruin instead of self-development. But this fact is not different from any other beneficial practice in life carried to extremes.

Medical science is dedicated to the betterment of health and the relief of suffering, and yet the misuse of drugs and the exultation of the physician's skills can lead people to a state where an individual's health is no longer within his or her personal control. A nutritious well-balanced diet works to keep a person alive, vital, and healthy, but grossly over-eating, over-drinking, or taking in too many chemicals is a sure way to poison the body.

Governments are established to oversee the harmonious inter-working of all parts of society, but when the rulers become greedy, hungry for power, or lacking in wisdom, the country is subjected to needless wars, disorder or civil and economic chaos.

A religion, when based on faith developed through experience, a broad and questing mind, and unflagging pursuit of universal understanding, is of inspiration and comfort to people. Once a religion loses its original focus, however, it becomes a deadly thing with which to deceive, control and tax the people through the manipulation of their beliefs and fears.

It is the same with the martial arts. The skills of self-protection, which should provide a feeling of inner peace and security for the martial artist, so often develop without a balance in the personality and lead the lesser martial artist into warped realms of unceasing conflict and competition which eventually consume him.

If an expert in the fighting arts sincerely pursues the essence of NINJUTSU, devoid of the influence of the ego's desires, the student will progressively come to realize the ultimate secret for becoming invincible - the attainment of the "mind and eyes of god". The combatant who would win must be in harmony with the scheme of totality, and must be guided by an intuitive knowledge of the playing out of fate. In tune with the providence of heaven and the impartial justice of nature, and following a clear
and pure heart full of trust in the inevitable, the NINJA captures the insight that will guide him successfully into battle when he must conquer and conceal himself protectively from hostility when he must acquiesce.

The vast universe, beautiful in its coldly impersonal totality, contains all that we call good or bad, all the answers for all the paradoxes we see around us. By opening his eyes and his mind, the Ninja can responsively follow the subtle seasons and reasons of heaven, changing just as change is necessary, adapting always, so that in the end there is no such thing as a surprise for the Ninja.