https://www.youtube.com/watch?v=60UuY8_tJqY
Dey was trained extensively in tessenjutsu in her younger years and continues to practice the art today.
Tessen: folding fans with outer spokes made of heavy plates of iron which were designed to look like normal, harmless folding fans. Samurai could take these to places where swords or other overt weapons were not allowed, and some swordsmanship schools included training in the use of the tessen as a weapon. The tessen was also used for fending off arrows and darts, as a throwing weapon, and as an aid in swimming.
Tessenjutsu (鉄扇術?)is the martial art of the Japanese war fan. It is based on the use of the solid iron fan or the folding iron fan, which usually had eight or ten wood or iron ribs.
The practitioners of tessenjutsu could acquire a high level of skill. Some became so skilled, in fact, that they were able to defend themselves against an attacker wielding a sword, and even kill an opponent with a single blow.
Apart from using it in duels against enemies armed with swords and spears, the skilled wielder could also use it to fence and fend off knives and poisoned darts thrown at him. Like a sword, the tessen could be dual-wielded to parry with one hand and attack with the other.
