Cache of swords,Japan,October 1945.
Most likely some were kept as souvenirs:
http://forums.gunboards.com/showthread.php?t=441/
War Department Cirs No. 155 and 267 (1945) authorized the issue of souvenirs to military and naval personnel who served in the SWPA during WWII. On the basis of these circulars, each officer and enlisted man received one of the following articles: rifle, carbine, saber, bayonet, pistol, or pair of binoculars. Responsibility for the collection of these items rested with corps commanders, who issued instructions for their distribution to field units under their respective commands. The War Trophy Depot, located in Yokohama, issued trophies to officers and men who were on orders to return to the US. A central issuing agency for fleet units within the Eighth Army area was established at Yokosuka Naval Base for distribution to naval personnel at sea"
An extract from "GHQ Supreme Commander Allied Forces (SCAP), Progress of Demob of the Japanese Armed Forces, dated 21 July 1948", listed the following:
Rifles & Carbines: Quantity captured & surrendered: 2,468,665. Disposed of Trophy, Museum, Technical use: 1,226,146.
Destroyed: 1,242,519. Returned to Japanese: None.
Bayonets: Quantity captured & surrendered: 1,568,254. Disposed of Trophy, Museum, Technical use: 713,832.
Destroyed: 854,422. Returned to Japanese: None.
Pistols & Revolvers: Quantity captured & surrendered: 81,061. Disposed of Trophy, Museum, Technical use: 62,760.
Destroyed: 9,559. Returned to Japanese: 8,742 (for use of civil police).
Swords & Sabers: Quantity captured & surrendered: 661,621. Disposed of Trophy, Museum, Technical use: 372,609.
Destroyed: 289,012. Returned to Japanese: None.
Automatic Weapons: Quantity captured & surrendered: 186,680. Disposed of Trophy, Museum, Technical use: 3,203.
Destroyed: 183,377. Returned to Japanese: None.
Since this report does not contain the raw data, I suspect that these numbers do not include battlefield pick-ups earlier in the war. However, given that a lot of the report touched on the demob of Japanese units overseas (and bringing them back to Japan, Customs Inspections, etc.) is may include numbers from other than the home islands, I do not know.
The books can be found online at:
http://www.army.mil/cmh/books/wwii/M...MacArthurR.htm