Located in Otsu City, Shiga Prefecture, Katata has a small inner lake. In the days when the Katada Kozoku developed Katata into the largest autonomous city, many boats went to Lake Biwa via waterways centered on the Inner Lake. The waterside was both a hangout for children and a laundry place, and life and the lake were deeply connected. However, due to the deterioration of water quality and the spread of cars, the current inner lake is isolated from people's lives and the city. In addition, the various livelihoods inherited by the Kozoku are also declining due to the aging of the workers. Therefore, in this project, by utilizing the livelihoods spun by the Lake tribe, we will reorganize the life with the waterside to revitalize the town of Katada in the future. For the architectural design, Marukofune's original construction method "Datekasugai," which was once responsible for the water transportation of Lake Biwa, is used to create a flow line for interaction between livelihoods and local residents. The date kasugai has the role of joining the base and board to the board. By creating a space at the boundary between land and water, it plays a role in connecting the inner lake and the town.