Sengoku Basara Samurai Heroes Cheats for Wii
Also on: PlayStation 3
To get one of the most powerful warlords of Japan's feudal age as a playable character complete Oichi's Story mode once, then start again, taking the Green route, following Tenkai when you reach Kobayakawa's stage, and killing Tenkai, and finish the route. Then return to any cleared character and look for a short grey alternate route near the end of one of their normal routes. Go down that route and follow the grey path, and clear the Honnoji stage.
When you beat Story mode with a character his/her alternate costume will become available.