As Japan entered the Modern era and acknowledged the outside world, it began to face many urgent problems. The modern Japanese police force also had many urgent problems in order to carry out its important mission. Neither the severe martial techniques of classical bujutsu nor the spiritually oriented ones of classical budo proved to be entirely usefulin their pure forms when applied to the work of the Japanese police force. From the time of the late Meiji era, the modern disciplines of kendo and judo have been useful to the Japanese police force primarily as systems of physical education. It remained essential that the police design their own formal system of hand-to-hand combat that would be more appropriate methods of self defence.

A technical study committee was assembled by the Tokyo police bureau in 1924. The committee members consisted of high-ranked swordsmen who were exponents of kenjutsu, kendo, and iai-do, and specialists in goshin-jutsu (self defence methods of jujutsu and judo). Members of the former groups were Nakayama Hyakudo, Hijama Yoshihitsu, Samura Goro, and Hotta SHitejiro; Nagaoka Shuchi, Mifune Kyuzo, Nakano Seizo, Sato Kinosuke, and Kawakami Tadashi represented the latter group. This committee devised a series of self defence techniques based on unarmed defence and recommended that these techniques be taught to all policemen. The police board approved the techniques and incorporated them into police training procedures with the condition that the techniques be given extensive study and testing.

The prohibitation of Martial Arts forced the Japanese government to request that the police force be allowed to at least develop and use a system of self-defence. Upon recieving approval of this reques, the Tokyo police burreau convened a new technical committee headed by kendoist Saimura Goro, judoist Nagaoka Shuichi, Shimizu Takaji, the twenty fifth soke (headmaster) of the Shindo Muso Ryu, Otsuka Hidenori, founder of the Wado Ryu, and Horiguchi Tsuneo, a pistol expert. This comittee reviewed the techniques of the classical kenjutsu, jujutau and jo-jutsu, and aadapted several techniques from each of these disciplines for police use, the committee also selected techniques from modern pisciplines, such as jujutsu, karate-jutsu, kendo and judo, for incorporation into the proposed system of self-defence; and further ideas were gained from a study of Western boxing. A system comprising these elements and called taiho-jutsu was created in 1947, and Taiho-jutsu Kihon Kozo (Fundamentals of Taiho-jutsu) was published as an official manual for policemen. Taiho-jutsu was later revised in 1949, 1951, 1955, 1962 and 1968. It will continue to be revised to prevent any of its theorys and techniques from becoming stagnent. The Japanese riot police now also practice Yoshinkan aikido in conjunction with their Taiho-jutsu. It is under constant study for furth possible revision. Great changes in social enviroment in Japan have made it neccessary fo rthe police to modify and so improve the system of taiho-jutsu. Though the emphasis on the simple restraint of assailants and other social offenders has not been removed, severe measures have had to be incorporated in the system so that the police can cope with the excessively violent tactics of some radical actovists. Taiho-jutsu has also been modifyed to permit the use of its techniques when the user is wearing heavey protective equpment (helmet, bulletproof vest, gloves, and shin guards).

The techniques designed by the first police technical study committee were largely based on classical discplines as modified by modern judo kihon, or fundamentals, such as posture, gripping, and body movement. Ten techniques of nage, or throwing, were the basis of the taiho-jutsu system. Eight techniques dealt with idori, or situations involving sitting postures; and six hiki-tate tactics, or those which bring an unwilling assilant to his feet so that he can be led away, were also devised. Little concern for the victim was shown in the execution of these techniques, which remained in use until after the end of World War II.

Whenever taiho-jutsu is used in the modern day it is applied so as to cause minimum damage to the assailant. An aggressor is to be confrounted, controlled, and subdued with safety for both the arresting officer and the prisoner; killing or maiming are measures to be avoided except for the most extream situations.

The concept of kobo-itchi, in which the priority of offensive or defensive actions depends on the appropriateness of either of the situations, is fully recognised in taiho-jutsu, wherre it is recognised as sen, oir initiative in combat. Sen is of three degrees. The first and the most desirable is sen sen no saki, or the ability to act in a way so as to control the assailant be they can launch an attack. Saki, the second level of sen, enables the arresting officer to join in an assailants attack, which has already started, and then gain advantage and control the attacker. Ato no saki, the third level of sen, is the ability of the arresting officer to receive a surprise attack and counter it.

Police men study taiho-jutsu in two ways, in toshu, or unarmed and also armed with a keibo, a short wooden club. There are fourteen kihon-waza (basic fundament techniques) of defence and sixten oyo-waza (advanced techniques); mastery of all techniques gives the officer the physical ability to deal with all normal hand-to-hand encounters. In addition the patrolman learns six techniqes dealing with seiji, or hand cuffing, soken, or searching methods, and hiki-tate oyobi, the restraining methods to bring the unwilling assailant to his feet and enable him to be led away, all the while onder control. Throughout the practice of taiho-jutsu the officer learns to use ma-ai, the appropriate combative distance, he learns to position himself so that he is close enough to his assailant to control him but too far away to be effectively attacked.

Techniques of taiho-jutsu alone are not enough. Every Japanese police man is expected to develop heijo-shin, the normal and tranquil state of mind that is manifest in a relaxed posture, normal breathing and confidence in what is being done. Through traing in taiho-jutsu the patrolman overcomes fear of an assailant and gains judgement of the situation and the abillity to make the proper use of techniques is what they aim to achieve through their training in taiho-jutsu. Among the many aspects of judging in a hand-to-hand situation are

1. the attitude of the assailant (offensive or defencive)

2. the number of assailants

3. the use of weapons

4. the capability of the assailant(s)

Practical situations involving armed and unarmed combat are part of taiho-jutsu training. Trainees wearing protective armor are allowed to wage combat against each other for the evaluation and development of the individual in the future.