Shingen's War Fan/Origin

Origin
One particularly famous legend involving war fans concerns a direct confrontation between Takeda Shingen and Uesugi Kenshin at the fourth battle of Kawanakajima. Kenshin burst into Shingen's command tent on horseback, having broken through his entire army, and attacked; his sword was deflected by Shingen's war fan. It is not clear whether Shingen parried with a tessen, a dansen uchiwa, or some other form of fan. Nevertheless, it was quite rare for commanders to fight directly, and especially for a general to defend himself so effectively when taken so off-guard.