A kodachi (小太刀) literally translates into "small or short tachi"; this Japanese sword was too short to be considered a long sword but too long to be a dagger. Because of its size, it could be drawn and swung extremely fast. Since this sword was shorter than 2 shaku in length, it did not exceed the blade length limits of non-samurai during the Edo period and could be worn by merchants.

Kodachi length is a bit greater than a standard wakizashi, and though the blades differ greatly in construction, the kodachi and the wakizashi are similar enough in size and technique that they are sometimes (mis)used interchangeably.

The prefix "ko" means short, and can be attached to any of the names of the swords to indicate something shorter than "normal". As the prefix "o-" means great/long, it follows that the opposite end of this length spectrum of the tachi is the odachi.

See also

• shoto
• wakizashi
• tachi

Kodachi Kuno is a character in Ranma ½.