There are various theories as to its origin, but as with the Tonfas, it is an agricultural tool converted into a Kobudo weapon. After the banning of the use of weapons by the peasants in 1609, and in the face of continuous attacks by the samurai, they began to use work tools for their defence.
The purpose of this weapon is to weaken the irrational violence of the adversary or in the face of a multi-person attack and thus defuse the situation, not to voluntarily attack. This is the reason why Sosetsukon kata always starts with defence.
There are various shapes, round, square or hexagonal, although the most popular is octagonal, like the one we have at Hajime Karate. Handmade in Japan from 33,5 cm red oak wood.