is a Japanese video game publisher, developer, and distributor founded in 1978.The company is known for its historical simulation games based on the novel Romance of the Three Kingdoms, as well as simulation games based on pseudo-historical events.
Yoichi was a student at Keio University, and when his family's rural dyestuffs business failed he decided to pursue his interest in programming.The company to this day is located in the Hiyoshi area of Yokohama along with Erikawa's alma mater.The company initially focused on personal computer sales and made-to-order business software.In 1983 it released Nobunaga's Ambition , a historical strategy game set during the Sengoku period of Japanese history.The game went on to receive numerous awards, and Koei produced several more such games set against the backdrop of world history, including Romance of the Three Kingdoms, set during the Three Kingdoms period of Chinese history, and Uncharted Waters , set in Portugal during the Age of Exploration.In 1988, Koei established a North American subsidiary, Koei America Corporation, in California.
This subsidiary localized Koei games for export to all territories outside Japan, as well as producing original games and concepts with the leadership of designer Stieg Hedlund, like Liberty or Death, Celtic Tales: Balor of the Evil Eye, Gemfire and Saiyuki: Journey West.
After Hedlund's departure, this subsidiary ceased game development in 1995, focusing instead on localization, sales and marketing. was established in early 2001, and a European subsidiary, Koei Limited was established in early 2003 in Hertfordshire, United Kingdom.
Koei also maintains subsidiaries in mainland China, Korea, Taiwan and Lithuania.
Recently, Koei created a Singapore branch for game development such as Sangokushi Online.
All Koei operations in English in turn ceased in 2012, with the previously unannounced closing of Koei's North American support forums and website.
They resumed in 2016, with the English language PC release of Romance of the Three Kingdoms XIII.