The tantō is a short edged weapon12 similar to a single or double-edged dagger with a blade length between 15 and 30 cm (6-12 inches).
At first glance it may be mistaken for a "small katana," but its design is actually different. Although the aesthetics are identical, the design of the blade and tsuka (hilt) are substantially simpler.
Generally, for reasons of etiquette, it is carried on the obi (belt), although it could certainly be concealed with relative ease.
Although the samurai's secondary weapon was the wakizashi (shorter version than the katana) or the kodachi (shorter version than the tachi), some samurai preferred the tantō for its ease of handling and as a complement to their melee martial arts.
As a ceremonial object it spread during the new era, replacing the wakizashi or the kodachi in the ritual of seppuku or harakiri (a suicide ceremony that the samurai performed in order to regain his honor after a dishonor).
Depending on the model, one can differentiate between tantō (with guard), hamidashi (with small guard) or aikuchi (without guard).
Wooden or plastic tantō also exist and are used for the practice of disarming techniques in traditional martial arts.
Styles of Japanese origin that include the use of a tantō in their programs for higher grades or dan are: