From StrategyWiki, the free strategy guide and walkthrough wiki

Koei
Founded	July 25, 1978
Founder(s)	Yoichi Erikawa, Keiko Erikawa
Located	Yokohama, Kanagawa, Japan
Website	http://www.koei.com/
Wikipedia has more about this subject: Koei

Koei Company, Limited (株式会社コーエー, Kabushiki-gaisha Kōē^?), formerly 光栄 (, Kōei^?) is a Japanese video game publisher and developer founded in 1978. The company is best known for its historical simulation games based on the novel Romance of the Three Kingdoms, as well as simulation games based on historical events.

The company has also found mainstream success in a series of loosely historical action games, the flagship titles of which are Dynasty Warriors (真・三國無双, Shin-Sangoku Musō^?) and Samurai Warriors (戦国無双, Sengoku Musō^?), the Musō (無双) series. Koei also owns two divisions known as Omega Force and Ruby Party, the latter of which focuses in dating sim games.

[edit] Divisions

Omega Force and Ruby Party are divisions of Koei.