Kendo, Judo, and Aikido are three of the most famous and traditional Japanese martial arts or Budo, that evolved into modern sports and became popular all over the world. These martial arts have a rich and long history that goes back to Japan's feudal period, with each of them having a different characteristics and concepts that contribute to their distinctiveness.

Kendo derives from the traditional Japanese swordsmanship known as kenjutsu which relies on the use of a bamboo sword or shinai and a protective armor or bogu. Today, around 6 million people practice Kendo globally.

Judo, which was founded by Jigorō Kanō in 1882, employs grappling and throwing techniques and applies the principle of maximum efficiency with minimum effort. This martial art, practiced by over 40 million people worldwide, is considered to be a very effective form of self-defense and is the only one among the three to be an Olympic sport.

Lastly, Aikido which was founded by Morihei Ueshiba in the early 20th century, emphasizes the use of an opponent's energy to gain control over them. It has become popular globally for its focus on harmony and peaceful resolution of conflicts. In addition to self-defense, it is also perceived as a tool for personal growth.

In Japan, these martial arts are still deeply rooted in the country's culture and history. They are often practiced in schools and universities, and many Japanese people continue to train in these martial arts as a way to stay physically fit and maintain their cultural heritage.