Sengoku is an RPG produced by Gold Rush Games. It is set in 16th century fuedal Japan (not surprisingly, known as the Sengoku-jidai or "warring states period"). The game system is compatible with Fuzion.
The game tries to be relatively accurate, but it is a fantasy roleplaying game. Since it is a fantasy game, it also incorporates a magic system, based on the legends of the time. This includes fantastical monsters and animals.
The full name of the game, according to the webpage, is Sengoku: Chanbara Roleplaying in Feudal Japan, but I've never heard that full title before.