Japan

Japan, officially the Empire of Japan, was a country in Asia before the Great War.

Pre-War
In 1941, during World War II, as part of the Axis Powers, the Empire of Japan attacked the United States at Pearl Harbor. One year later, the Sierra Army Depot was constructed to defend the United States should Japan attack the West Coast. In 1945, the United States military dropped two atomic bombs on the Japanese cities of Hiroshima and Nagasaki, the bombs being named "Little Boy" and "Fat Man" respectively. This was the first time nuclear weapons had been deployed in combat between nations, and the only such event to occur before the Resource Wars.

The pre-War Battle of Iwo Jima is depicted on a mural in the Museum of Freedom in Concord, and the Battle of Okinawa is mentioned in tandem with other pre-War conflicts such as the Battle of Anchorage, Antietam and Amiens.

The Pioneer Scouts codebreaker exam provides Japanese as a possible answer to the question, "Which of these patriotic languages did our fine fighting men use as an unbreakable code during World War II?" The Pioneer Scout herpotologist exam also mentions the Japanese giant salamander.

The Watoga High School marching band was set to go on a field trip to the country before the war.

Two adolescent girls in the Clarksville area, known to have spent a lot of time near a local river, went missing. Calvin van Lowe suspected that they might have been taken by kappas, river monsters from Japanese folklore.

Post-War
In 2241, some descendants of the Yakuza, the pre-War Japanese mafia, inhabit the area around New Reno, perpetuating the tradition of their expertise in swordplay and throwing weapons. They carry short swords known as wakizashi. They have no known headquarters and travel in small bands, fighting against New Reno's mobsters and scouting the wasteland around New Reno. Additionally, prostitutes in New Reno have knowledge of anime, a style of animation from Japan, and will mention it when being approached by the Chosen One in power armor.

In 2277, Toshiro Kago, a samurai of the Oda clan born sometime before 1562 during the Sengoku period, was found aboard Mothership Zeta by the Lone Wanderer after being abducted by aliens seven centuries earlier.

Weapons of Japanese ancestry such as katanas can be found in the Mojave Wasteland, as can throwing stars in the Midwest.

Some robots seen in the Commonwealth speak Japanese. In 2282, Takahashi, a Protectron, has been set up to work at Power Noodles. The only thing he can say is "Nan-ni shimasu-ka?" (なんにしますか？) or "What will you have?" The mayor notes that this could be due to malfunction. The companion Curie will ask Takahashi about the menu. When he responds with his usual greeting, she will introduce herself to him in Japanese, saying "Watashi wa Curie desu" (私はキュリーです) which means "I am Curie."

The Nakano family in the Commonwealth, including Rei, Kenji, Taichi, and Kasumi, have names that are of Japanese origin.

Mount Fuji, a major volcano on the island, is an incorrect answer to one of the questions in the Pioneer Scout exams.

Appearances
Japan is mentioned in Fallout 2, Fallout 3 and its add-on Mothership Zeta, the Fallout: New Vegas add-on Gun Runners' Arsenal, Fallout Tactics, Fallout 4, Fallout 76 and the update Wild Appalachia. It may have appeared in the canceled Fallout Extreme.