Basic idea of Satoumi was first proposed by the late Professor Tetsuo Yanagi in 1998. Widely known definition of Satoumi is “a coastal area where biological productivity and biodiversity have increased through human interaction”. Satoumi activities can be classified into 7 types from the 2 major viewpoints. One is the place where Satoumi activity is made, for example, fishing village, urban area, river basin etc. and the other is the main group of people who participate in the activity. Satoumi born in Japan is said to be grown up in the Seto Inland Sea, Japan. Main reason is that the sea had suffered from serious water pollution and environmental destruction during the age of high economic growth after WWII. Strong counteraction against environmental pollution and destruction which aimed at environmental restoration and remediation occurred in 1970s. Those were historical background of Satoumi which was born in the late 1990s and developed in twenty-first century. In this article, varieties of present Satoumi creation activities in the Seto Inland, Japan are to be introduced according to the type of Satoumi. In many deteriorated enclosed coastal seas, only “passive (preventive) conservation” is not enough but “active conservation” such as Satoumi with human interaction is necessary. Among many types of “active conservation”, Satoumi which is community-based “active conservation” with people’s participation, is vital to realize resilient coastal seas and to reconstruct better relationship between human and the coastal sea towards SDGs-based human well-being.