[2] It began as samurai warriors' customary swordsmanship exercises,[3] and today, it is widely practiced within Japan and has spread to many other nations across the world.

[5] Formal kendo exercises known as kata were developed several centuries ago as kenjutsu practice for warriors.

[7] Yamada Heizaemon Mitsunori (Ippūsai) (山田平左衛門光徳(一風斎), 1638–1718), third son of Naganuma and the eighth headmaster of the Kashima Shinden Jikishinkage-ryū Kenjutsu, is credited with improving the art with Japanese wooden and bamboo swords, according to his gravestone's inscription.

[8] Naganuma Sirozaemon Kunisato (長沼四郎左衛門国郷, 1688–1767) inherited the tradition from his father, Heizaemon, in 1708, and the two of them collaborated to improve what would become modern kendo training armor.

[7][8] Shūsaku Narimasa Chiba (千葉 周作 成政, 1792–1855), founder of the Hokushin Ittō-ryū Hyōhō (北辰一刀流兵法), introduced gekiken (撃剣) (full-contact duels with bamboo swords and training armor) to the curriculum of tradition arts in the 1820s.

Due to the large number of students of the Hokushin Ittō-ryū Hyōhō at the end of the Edo period, the use of bamboo swords and armor as a form of practice became popular.

[7][9][10][11] After the Meiji Restoration in the late 1800s, Sakakibara Kenkichi popularized public gekiken for commercial gain, resulting in increased interest in kendo and kenjutsu.

However, it proved difficult to integrate all sword arts, leading to a compromise of ten practice moves (kata) for police training.

The Junsa Kyōshūjo (Patrolman's Training Institute), founded in 1879, provided a curriculum that allowed policemen to study gekiken during their off-hours.

The Dai Nippon Butoku Kai (DNBK) was established in 1895 to promote martial arts in Japan.

It changed the name of the sporting form of swordsmanship, gekiken, (Kyūjitai: 擊劍 and Shinjitai: 撃剣, "hitting sword") to kendō in 1920.

This was part of "the removal and exclusion from public life of militaristic and ultra-nationalistic persons" in response to the wartime militarization of martial arts instruction in Japan.

According to a survey conducted by AJKF, the number of active kendo practitioners in Japan is 477,000, including 290,000 dan holders.

[31] The shinai is meant to represent a Japanese sword (katana) and is made up of four bamboo slats which are held together by leather fittings.

[32][33] Age Group Shinai Size[34] Kendōka also use hard wooden swords (木刀, bokutō) to practice kata.

The forearms, wrists, and hands are protected by long, thickly padded fabric gloves called kote (小手).

The clothing worn under the bōgu comprise a jacket (kendogi or keikogi) and hakama, a garment separated in the middle to form two wide trouser legs.

Additionally, kendōka execute fumikomi-ashi (踏み込み足), an action similar to a stamp of the front foot, during a strike.

Strikes are only made towards specified target areas (打突-部位, datotsu-bui) on the wrists, head, or body, all of which are protected by armor.

The kendōka and motodachi practice the technique slowly at first; as familiarity and confidence build, they increase the speed to the level used in matches and competitions.

A good example is Hikibana-kote when a strike is made to an opponent's kote as they feel threatened and raise their kensen as the initiator pushes forward.

Here a skillful use of the kensen and spirited attack is crucial for effective katsugi-waza or luring the opponent into breaking their posture.

For success, the distance between oneself and the opponent has to be correctly perceived, and then one knocks down their shinai before their arm fully extends.

A scorable point (有効打突, yūkō-datotsu) in a kendo competition (tai-kai) is defined as an accurate strike or thrust made onto a datotsu-bui of the opponent's kendo-gu with the shinai making contact at its datotsu-bu, the competitor displaying high spirits, correct posture and followed by zanshin.

[38] Zanshin (残心), or continuation of awareness, must be present and shown throughout the execution of the strike and the kendōka must be mentally and physically ready to attack again.

To award a point, a referee raises the flag corresponding to the color of the ribbon worn by the scoring competitor.

Eighth-dan (八段, hachi-dan) is the highest dan grade attainable through a test of physical kendo skills.

The kata include fundamental techniques of attacking and counter-attacking, and have useful practical application in general kendo.

[48] In 2003, the All Japan Kendo Federation introduced Bokutō Ni Yoru Kendō Kihon-waza Keiko-hō (木刀による剣道基本技稽古法), a set of basic exercises using a bokuto.

This form of practice is intended primarily for kendōka up to second dan (二段, ni-dan), but is very useful for all kendo students who are organized under FIK.