While the Uesugi and Takeda armies clashed in mortal combat, a lone mounted warrior with a white cowl covering his head rushed into Shingen's battlefield headquarters, directly at Shingen, who was sitting at his camp stool, and drew his sword. Shingen had no time to draw his sword, and instead was forced to catch the blows on his war fan. Shingen's attendant, Hara Osumi no kami, ran to Shingen's aid, and struck at the rider with a spear but missed, hitting the horse instead. The horse reared, and the mounted warrior retreated.
This is the same famous scene found in books and movies; The warrior in the white cowl is Uesugi Kenshin, and Takeda Shingen's warfan bore eight sword cuts. However, did this really happen as described, or is this just the stuff of legends? It is plausible. Kenshin is known to have held Minamoto Yoshitsune in high esteem, and as such always rode with his men, and personally led his men into battle to emulate his hero. It would not be unreasonable for him to have made his way to Shingen's camp. According to one book (Sengoku Busho Omoshiro Jiten), there are historical records that have been discovered that dispute this personal combat. According to this book, the Kenshin Nenpu (Kenshin Chronological Record), states:
Arakawa, who was dressed as Kenshin, rode at Shingen and attacked. Shingen was unable to draw his sword, and so blocked with his war fan. Hara Osumi no kami ran to Shingen's aid, and drove off the mounted warrior.Arakawa Izu no kami was supposed to have been Kenshin's kagemusha (double) during the 4th battle of Kawanakajima (although I couldn't seem to find him in the Sengoku Jinmei Jiten). According to the above source, it is thought that the man that Shingen fought at Kawanakajima was Kenshin's kagemusha, rather than Kenshin himself. To further confuse the issue, according to the Hokuetsu Gunki, some time after the battle, Shingen received a visit from a monk by the name of Tenkai, who would later become an advisor to Tokugawa Ieyasu. Tenkai would tell Ieyasu that Shingen told him during thier meeting that "the man who fought with Kenshin that day was not me, but someone who looked like me". Meaning that apparently it wasn't Shingen but his Kagemusha that fought off the attack.
We are left with the somewhat boggling possibility that that they were both kagemusha. Moreover, it is believed that Kenshin and Shingen had never seen each other's face, which likely would also have added to the confusion. Although the personal combat between Kenshin and Shingen is recorded in the Koyo Gunkan, there doesn't seem to be any other additional evidence to support this, however I only flipped through a few books in preparation for this post, so I welcome any comments or sources to dispute or enhance what I have here. In particular, I have to wonder if Terje Solum's Saga of the Samurai series (Which I don't have, but is on my "to buy" list) on the Takeda clan covers this.
Some references for this post:
Koyo Gunkan. (Edited by Yoshida Toyo), 19th edition, Tokyo, August 2005.
Narumoto, Tatsuya. Sengoku Bushou Omoshiro Jiten, Japan, 1998
Sato, Hiroaki. Legends of the Samurai, Overlook, 1995
Arakawa Izu no kami - SamuraiWiki