Kaminoseki is a port-town and fishing town on the Inland Sea coast of Yamaguchi prefecture (formerly Suô province). It is situated across three islands and a small peninsula of "mainland" Honshu, and incorporates a number of formerly distinct villages, including that of Murotsu. A major regional harbor not only for local/regional traffic but even for foreign voyagers, Kaminoseki or areas immediately nearby appear in records as early as those written by ambassadors from Silla in the 8th century, recorded in the Man'yôshû, as well as records associated with Korean and Ryukyuan embassies to Edo in the 17th-19th century, and in diaries and journals of Western travelers such as Carl Peter Thunberg in the 1770s, and Robert Fortune in the 1860s.
In the 16th century, Kaminoseki was one of a number of major bases of the Murakami clan "pirate" navy. The Murakami maintained a castle in the area, and enjoyed authority from the Môri clan (the dominant clan in the region) to exact tolls and custom fees from ships entering or passing by the harbor. This castle was eventually demolished, and the Murakami's piratical activities outlawed in 1588, but the Murakami maintained sub-fiefs in some of the surrounding regions (namely Iwaishima and parts of Nagashima) into the Edo period. Meanwhile, the Môri, now based in Hagi (on the northwestern coast of Yamaguchi pref.), reallocated many of the sub-fiefs in 1625, bringing portions of Kaminoseki (including Murotsu and parts of Nagashima) along with much other territory in the domain, more directly under Môri control.
Today, the town is perhaps most known for the nuclear power plant which was proposed to be constructed in the 1980s, and which as a result of local protests, has been delayed and delayed, essentially blocked, and today more than 30 years later still has not been built; many of those opposing the construction of the power plant argue that they do so, in part at least, in order to protect their hometown (furusato), though there are also many in favor of the power plant who argue similarly that its construction will help revive the town, which has seen considerable decline as have many rural areas in Japan in recent decades.
- Martin Dusinberre, Hard Times in the Hometown: A History of Community Survival in Modern Japan, University of Hawaii Press, 2012.