Koei is a Japanese video game company known for developing and publishing games, particularly in the action and strategy genres. Founded in 1978, it gained popularity for its historical simulation games, especially the Dynasty Warriors series, which features characters from Chinese history. In 2003, Koei merged with Tecmo, another prominent game developer, to form Koei Tecmo Games. This merger expanded their portfolio, allowing them to create a wider variety of games, including the Ninja Gaiden series and the Atelier series, which are well-received by gamers worldwide.