Maisou Matsuri is a fire festival held on January 14th every year, and is a traditional practice that is dedicated to the Mii Shrine. Japanese devils, or oni are hit on by locals to wish for a healthy year. The oni wear kokimen or masks, and hold wooden shields called kiboko.
According to a legend during ancient times when the area was mostly muddy waters a god was riding a 3-boat ship and while looking around he could not find where two of the ships went. The god said "Naisouya" (it doesn't seem like we'll find it) while looking for the ships, but then found one in Miyamoto in Oya, and then said "Maisoya" while searching and found the other ship in Funaya in Yabu. After finding all of them he would say "Atta! Atta!" and the festival was called Nehune Matsuri or Emi Sai. As the god was looking for the last final ship he would say "Ma-Issou nai" meaning I cannot find the last boat, and he relentlessly continued to search until the night because of this the festival was called Maisou Festival.
After the sacred matters are held at the main shrine, participants form into a circle and each hold torches that are lit by the god's sacred fire. 3 people play the role of the devil and they move to the beat of the drums. The first oni holds a wooden box in their right hand and a wooden weapon on their left and jump out from the main shrine. They move as if they are stepping shiko (sumo wrestling stepping pattern) and they move around the circle of people in a counterclockwise manner. The participants shout "Maiso-nai" and wave the fire torches from above their head and viciously smack the wooden box held by the oni. The second and third oni follow the same pattern and after going around the circle a total of three times they make howling sounds and return back to the main shrine.
Mii Shrine 481 Oyacho Miyamoto, Yabu City