Yamaksa Dictionary

The Shout “Osshoi”:
While the origin of the shout is unknown, it is assumed, that it is connected with the name of the first event, called “Oshioitori”. This event is a ritual for the safety of the festival and could be the reason why “Osshoi” is shouted when going slowly with the Kakiyama.
The shout has a rhythm, that the spectators reinforce by clapping the the beat. It is believed, that the shout “Oisa”, that is used when going faster, is just a shorter version of “Osshoi” and is used because it has no rhythm, that the carriers would have to adjust to.