The State of Japan (日本 Nippon) is an Asiatic island nation located in the Pacific Ocean, east of the Sea of Japan. One of the world's greatest powers, Japan is well known for many achievements, including having the largest metropolitan center in the world (Tokyo), the world's tenth largest population at over 127 million, the third largest economy by nominal GDP and the world's highest levels of life expectancy.
In the aftermath of the 2007-2010 global economic crisis, Japan was the first country attacked by the Valahia as part of the Golden Axe Plan. Tokyo was invaded by an aerial force led by the Spiridus, but the attack was repelled by the Japan Self-Defense Forces and Martinez Security, a private military company. Further invasions occurred over the Izu Islands, the Boso Peninsula and Tokyo itself, the latter involving an giant aircraft Orgoi, but these also ended in failure.
In the Horizon universe, Japan followed a similar timeline to the real world, including the transition to the Meiji period and its involvement in World War II. However, a minor divergence took place in the postwar period, where the lifting of the ban on indigenous aircraft production by the Supreme Commander for the Allied Powers took place in 1956, rather than 1952. After the American occupation of the country, the industry of the country experienced a major surge, which included the transition of Taiga Heavy Industries into an aviation company.
The September 11 attacks, combined with the unauthorized incursion of two CFA-44 Fandance jets in May 2002, caused the Japanese government to reinforce its stance on national defense, leading to the development of the F-3 Shinden II by Taiga. In the aftermath ot the failed uprising on Russia in 2016, the country became the target of operations by New Russian Federation remnants to destabilize the region. Several incidents occurred over the next years, including the Haneda bombing in Tokyo in 2018 and a full attack on the city the year after, which was foiled by the four ASF-X Shinden II test units.
Japan was one of the countries that suffered damage during the Ulysses Disaster. Central Japan suffered several impacts, and the destruction in Tokyo forced the authorities to relocate the status of capital to another city.
Two decades after the event, Japan faced an attack by the Sons of Troia using MQ-90 Quox drones. After the USEA Federation Proclamation established the USEA Federation throughout Eurasia, Japan became the front line for the United Nations Forces and was the site of many skirmishes between the two forces, with Tokyo seeing repeated combat and attempted destruction from the SOLG program.