The warriors of The Three Kingdoms were Chinese and thrived in the 3rd Century AD. The most famous Japanese Warriors, the Samurai were established in the 12th Century AD.
I'd say the end of the end of the Heian. You have the Genji and the Hekei Fighting. THen the Sengoku Jidai period where Japan was devided. Then the Bakumatsu and Bonin war were the last major incedents with Samurai.
