This report aims at understanding Oginoshima village’s environmental maintenance system by focusing on groups in the village. A mutual-aid group based on agreements between houses called Atari has a mesh-like structure that covers the entire village by each house having several Atari relationships, while an administrational group called Tonarigumi is based on a neighborhood. Moreover, Tonarigumi has been reorganized in a way that complements weaker connections of Atari in response to changes through time. The analysis shows that Atari and Tonarigumi are complementing each other to form a connection throughout the village by the overlapped layers of those characteristic structures.
