In the first conflict between Shingen and Kenshin they were very cautious, only committing themselves to indecisive skirmishes. There were a total of five engagements at Kawanakajima. Only the fourth battle was a serious, all-out battle between the two. During the fourth battle, Kenshin's forces cleared a path through the Takeda troops and Kenshin engaged Shingen in single combat. Kenshin attacked Shingen with his sword while Shingen defended with his Japanese war fan (tessen). Both lords lost many men in this fight, and Shingen in particular lost two of his main generals, Yamamoto Kansuke and his younger brother Takeda Nobushige. After the death of Shingen, Tokugawa Ieyasu borrowed heavily from Shingen's governmental and military innovations after he had taken leadership of Kai Province during Toyotomi Hideyoshi's rise to power. Many of these designs were used by the Tokugawa shogunate.