The name "Shonan" of this Japanese region already existed in the 17th century, relative to Shigitatsu-an, according to Ōiso Town. During the 1880s, when the custom of swimming in the ocean was introduced into Japan, the "Shonan" region became a resort area for the politicians and rich people from Tokyo. In postwar times, the Shōnan region gained prominence in Ishihara Shintaro's prize-winning 1955 novel, Taiyō no Kisetsu. The novel, which was also made into a popular movie, portrayed the hedonistic lifestyle of young sun-worshippers from elite families, who hung out on Shōnan beaches. Lying as it does on the edge of the Tokyo-Yokohama metropolitan area, the Shōnan region is nowadays a leading resort area, oriented to surfing, sailboating, and other water sports.
Etymology
There are two theories in the etymology of Shōnan. One is that Kanagawa Prefecture where the Shōnan region is located was until the first half of the19th century called Sagami-no-kuni or Sōshū , and that Shōnan was in the south of Sōshū. The other is that Shōnan comes from Xiangnan County of the old Province/Country of Changsha in southern China. In the latter theory, the region's name, Shōnan, derives from a supposedly scenic region in Hunan, China, encapsulated in the phrase 瀟湘湖南. This phrase refers to a beautiful area centered on the Xiao River and the Xiang Riversouth of the Yangtze River in Hunan. Often praised in Chinese poetry of the Xiaoxianggenre, the scenery of this area became a stylized popular subject of paintings in both medieval China and Japan, particularly as to the graphic and poetic series known as the "Eight Views of Xiaoxiang". In Japan, the scenery of the Shōnan area was thought to be similar to the scenery around the Xiao and Xiang rivers in Hunan, China; hence the term "Shōnan" came to be applied to the area around Enoshima in Japan. Besides the similarity in scenery, the two areas both had flood-basin lakes. The lake in China, which still exists, is Lake Dongting. Among others, the lake is fed by the Xiang and Xiao rivers. In Japan, the corresponding flood-basin lake was probably located along the course of the Kashio River, which flows into Sagami Bay at Enoshima.