[3][better source needed] It is portrayed by modern ninjutsu practitioners (including Masaaki Hatsumi[4] and Stephen K. Hayes) as the weapon of the ninja, and features prominently in popular culture.
[1] Because of the lack of any physical evidence or antique swords from the Sengoku to the Edo matching the description of the ninjatō,[1] the history of the weapon can only be chronicled reliably from the 20th century onwards.
The ninjatō is typically depicted as being a short sword, often portrayed as having a straight blade (similar to that of a shikomizue)[17] with a square guard.
Despite the disputed historical existence of the ninjato,[12] Hayes claims to describe it in detail, and suggests that the typical description of the ninjatō could be due to ninja having to forge their own blades from slabs of steel or iron with the cutting edge being ground on a stone, with straight blades being easier to form than the much more refined curved traditional Japanese sword.
[22] Contemporary sources allege the scabbard was used for various purposes, such as a respiration pipe (snorkel) in underwater activities or for secretly overhearing conversations.