Japan

Japan was a country before the Great War, located in Asia.

Background
Tokugawa Ieyasu created the Tokugawa shogunate in medieval Japan.

In 1941, the Empire of Japan attacked the United States of America at their air force base in Pearl Harbor and sparked American involvement in World War II. One year later the Sierra Army Depot was constructed to defend the United States should Japan attack the west coast. In 1945, the Japanese surrendered to the United States after the United States developed and deployed two atomic bombs on the cities of Hiroshima and Nagasaki.

After World War II, not much is known of post-war Japan and whether it progressed along a similar path as real-world Japan, but it would be in good standing with the United States circa 2077, with Pioneer Scouts codebreaker exam proclaiming Japanese as a patriotic language. Almost nothing is known about the country after the Great War, however.

In 2241, some descendants of the Yakuza, the pre-War Japanese mafia, are around New Reno, perpetuating the tradition of their expertise in swordplay and throwing weapons. They have no known headquarters and travel in small bands, fighting against New Reno's mobsters and scouting the Wasteland around New Reno. They never succeed in entering into the city, however.

In 2277, Toshiro Kago, an old samurai born sometime before 1562 during the Sengoku period, was found aboard mothership Zeta by the Lone Wanderer.

Appearances
Japan is mentioned in Fallout 2, Fallout 4, Fallout 76, although Yakuza and the wakizashi appeared in Fallout 2, and Toshiro Kago, with a katana, okegawa dô and the kabuto appeared in the Fallout 3 add-on Mothership Zeta. The Katana appears in the Fallout: New Vegas add-on Gun Runners' Arsenal. The Shishkebab from Fallout 4 and Fallout 76 is also built around a katana.