Takeshi no Sengoku Fuuunko

Start a new "SENGOKU GAME", and when asked "How many players would you like?", choose the number of players,. Before pressing the A button on Controller 1, press and hold Up + Left + B on Controller 2. You'll be asked for another question: "How many human players would you like?", so you can select from one to four human controlled players; the rest of the players will be CPU controlled.