There are 3 lengths in Swords carried by the Japanese Samurai. The longest is a Katana, next is a Wakazashi and the shortest more like a dagger is a Tanto. If the hand gaurd (Tsuba) is oval or round and the blade slightly curved then it is generally a samurai type sword. If the Tsuba is square and the blade straight it is a Ninja type sword. If you get get a pic or two I will try and point you in the right direction.