In early Heian Period (7th century), Sosuke and Kosuke of wood craft men from Kiso Town visited Hida Suimu Shrine. Someday, Hida was involved in the war and they carried Mikoshi out of Hida to save the sacred treasure of Shrine. When they passed the mountains between Hida and Kiso, other people reached them and tried to bring back their Mikoshi.
They drop Mikoshi to the valley and finnaly escaped from the war.
Based on this legend, people in Kiso imitate this event and created Matsuri to break Mikoshi. During the Mikoshi Makuri, people call Sosuke and Kosuke to show the respect of them.