Sengoku Rance, a hentai visual novel and war strategy game hybrid, developed by Alice Soft. Released in Japan in December 15th, 2006. The game has not been officially localized in the west, but a fan translation patch is available. No voice acting. Censored genitals. Available for PC Windows.
Sengoku Rance takes place in an alternate version of the Sengoku period of Japan. Many historical figures and locations have been parodied. The premise of the game is that you are a foreigner called Rance, who has come to Japan for a hot spring vacation. The Oda house, which was once the most powerful in the nation of Japan, has declined with Oda Nobunaga’s failing health. Since Oda himself can no longer command his troops, he nominates Rance to take over.