The Japanese word wakizashi literally means “side arm.” The wakizashi sword is a short sword with a curved blade. Its short size makes it easier for use in off hands when wielding two weapons. It was most commonly used by samurai in feudal Japan, and first appeared somewhere in the fourteenth century.
The wakizashi sword was typically used in conjunction with a longer blade, often a katana, which translates to “long sword.” The term for wielding two weapons in Japan is daisho, which means “long and short.” Wakizashi can be up to 60 centimeters (24 inches) long. Any blade shorter, when used in the style of wakizashi swords, is a wakizashi. The shorter length allowed better balance in the usually weaker offhand.
There isn’t an official length that denotes wakizashi swords. Daggers and other short swords can all be considered wakizashi. The rulers of feudal Japan attempted to regulate use and display of the daisho that the people were able to wear to elevate the status of samurai. There were large groups of bandits who broke the laws and who would even wear wakizashi of equal length to their katanas.
Wakizashi longer or shorter than their prescribed length were given a prefix. "O-" was given to longer swords and "Ko-" to shorter swords, such as Ko-wakizashi. A habaki was located under the hilt of the wakizashi sword to secure it in place while in its scabbard. The grip of the sword would be wrapped in cloth to absorb sweat and reduce slipping.
Wakizashi were used in combat as back-up weapons, for dual wielding, for decapitating foes, and for committing ritual suicide. This caused foreigners to call it the “honor blade.” Ritual suicide, or seppuku, is one of the most distinguished and respectable acts someone can commit in the traditional Japanese culture.
Collecting heads from slain enemies on the battlefield for trophies was a common practice in feudal Japan. The warrior would have to hold the struggling victims head in place with one hand and slice the head off with the other. The shorter blade on the wakizashi sword made it much easier to accomplish. It was also used to save the blade on the katana to prevent unnecessary damage.
Samurai never parted from their wakizashi sword. When entering another home, the katana would have to be given to a servant to reduce suspicion, but the samurai was allowed to keep the wakizashi for personal protection. A wakizashi was worn from the time the samurai woke to the moment he went to bed, and then he would sleep with it under the pillow.