"Gakkogura" is a place where Obata Sake Brewery, a long-established sake brewery founded in 1892, renovated an abandoned school on Sado Island into its second sake brewery in 2014. Sake is brewed here in the summer and is operated under the four pillars of "sake brewing," "coexistence," "exchange," and "learning." Sake is brewed using raw materials that conserve biodiversity and renewable energy from solar panels, and the by-products, sake lees and koji, are served as fermented dishes combined with ingredients from local producers at the Gakkogura Cafe within the facility, which also helps reduce food waste. Participants from Japan and abroad gather for long-term stays such as the "Sake Brewing Experience Program" and workshops such as "Special Classes at the Gakkogura," which also teach about the local circulation, and the community is expanding every year.