The Japanese Kodachi is a type of sword that originated in Japan. It is characterized by its shorter length compared to other traditional Japanese swords, such as the katana or tachi.

The Kodachi typically has a blade length ranging from around 50 to 65 centimeters (20 to 26 inches), although the exact measurements can vary. This shorter blade distinguishes the Kodachi from longer swords like the katana, which often measure around 70 to 80 centimeters (28 to 31 inches) in blade length.

Historically, the Kodachi was used as a secondary weapon by samurai. It was commonly employed in close-quarters combat or indoor settings where a longer sword would be less practical. The shorter length allowed for quicker and more agile movements in confined spaces.

The Kodachi shares similarities with the traditional Wakizashi sword, which is also shorter than the katana but longer than the Kodachi. While the Wakizashi was typically the sidearm of the samurai, the Kodachi was even shorter and often used in specific contexts where its compact size was advantageous.

It's important to note that the terminology and specific characteristics of swords can sometimes vary, and there may be different interpretations or variations of the Kodachi. However, generally speaking, the Kodachi is understood as a shorter sword that served as a companion weapon to longer swords like the katana.