Shoto is a length designation for Japanese swords. The three main divisions of Japanese blade length are: 1 shaku (30.3cm) or less for tanto, 1-2 shaku for shoto, and 2 shaku or more for daito. These are measured in a straight line across the back of the blade from tip to munemachi (where blade meets tang). Most blades that fall under this size range are wakizashi, however some daito were designed with blades slightly shorter than 2 shaku. These oddballs were called kodachi and are somewhere in between a true daito and a wakizashi. A shoto makes up one half of the typical armaments of the samurai called daisho for both long and short sword.
The Nanpo Shoto is a chain of Japanese islands extending from the Izu Peninsula west of Tokyo Bay southward for about 750 miles (1200 km), to within 300 miles (500 km) of the Mariana Islands.
The Nanpo Shoto consists of three major groups of islands: the Izu Shoto ; the Ogasawara Gunto, also known as the Bonin Islands; and the Kazan Retto, also known as the Volcano Islands.
Among the latter group of islands lies IÅjima or Iwo Jima, located about 670 miles south of Tokyo, 700 miles north of Guam and nearly halfway between Tokyo and Saipan.