A number of war fans were used in Japanese feudal warfare, of varying size and material, for different purposes. One of the most significant, and perhaps most interesting, uses was as a signalling device. Signalling fans came in three varieties: a tasseled pom-pom, a solid iron fan, or a wood and paper one, very similar to the fans used today by sumo referees.

The commander would raise or lower his fan and point in different ways to issue commands to the soldiers, which would then be passed on by other forms of visible and audible signalling. The art of fighting with war fans is tessenjutsu.

War fans in history and folklore

One particularly famous legend involving war fans concerns a direct confrontation between Takeda Shingen and Uesugi Kenshin at the fourth battle of Kawanakajima in 1561. 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.

Minamoto no Yoshitsune is said to have defeated the great warrior monk Benkei with a tessen.

Araki Murashige is said to have used a tessen to save his life when the great warlord Oda Nobunaga sought to assassinate him. Araki was invited before Nobunaga, and was stripped of his swords at the entrance to the mansion, as was customary. When he performed the customary bowing at the threshold, Nobunaga intended to have the room's sliding doors slammed shut onto Araki's neck, killing him. However, Araki supposedly placed his tessen in the grooves in the floor, blocking the doors from closing.

The Yagyū clan, sword instructors to the Tokugawa shoguns, included tessenjutsu in their swordschool, the Yagyū Shinkage-ryū.

War fans in popular culture

War fans are frequently featured in Japanese popular culture, especially anime and manga. Oftentimes they are used when one character hits another in frustration, most famously Genjyo Sanzo in Saiyuki and Kaname in Full Metal Panic!. Additionally, Yumi Ishiyama in the French animated series Code Lyoko uses war fans as her weapons, as do Mai Shiranui of Fatal Fury, King of Fighters, Anji Mito of Guilty Gear X, and Kitana of Mortal Kombat, and Temari from Naruto fights with a giant metal fan. Even Kagura from the anime Inuyasha wields a fan to use her powers. Tasuki from Fushigi Yūgi is also known for wielding a flaming war fan. The Kyoshi Island Warriors from Avatar: The Last Airbender use metal fans as their primary weapon and even utilize retractable fans as wrist shields. The psychopathic character Kazuo Kiriyama is given a harisen in the movie Battle Royale. Also, in Super Mario RPG, one of Princess Toadstool's weapons is a War Fan.