Hachijō-jima in the context of Ryokan (Japanese inn)

The small group of Hachijō dialects (八丈方言, Hachijō hōgen), natively called Shima Kotoba (島言葉; [ɕima kotoba], "island speech"), are, depending on classification, either the most divergent form of Japanese, or comprise a branch of Japonic languages (alongside mainland Japanese, Northern Ryukyuan, and Southern Ryukyuan). Hachijō is currently spoken on two of the Izu Islands south of Tokyo (Hachijō-jima and the smaller Aogashima) as well as on the Daitō Islands of Okinawa Prefecture, which were settled from Hachijō-jima in the Meiji period. It was also previously spoken on the island of Hachijō-kojima, which is now abandoned. Based on the criterion of mutual intelligibility, Hachijō may be considered a distinct Japonic language, rather than a dialect of Japanese.

Hachijō is a descendant of Eastern Old Japanese, retaining several unique grammatical and phonetic features recorded in the Azuma-dialect poems of the 8th-century Man'yōshū and the Fudoki of Hitachi Province. Hachijō also has lexical similarities with the dialects of Kyushu and even the Ryukyuan languages; it is not clear if these indicate that the southern Izu islands were settled from that region, if they are loans brought by sailors traveling among the southern islands, or if they might be independent retentions from Old Japanese.

Fuji-Hakone-Izu National Park (富士箱根伊豆国立公園, Fuji-Hakone-Izu Kokuritsu Kōen) is a national park in Yamanashi, Shizuoka, and Kanagawa Prefectures, and western Tokyo Metropolis, Japan. It consists of Mount Fuji, Fuji Five Lakes, Hakone, the Izu Peninsula, and the Izu Islands. Fuji-Hakone-Izu National Park covers 1,227 square kilometres (474 sq mi).

Rather than being a specific spot, the park is a collection of dispersed tourist sites that dot the region. The farthest point south, the isle of Hachijō-jima, is several hundred kilometers from Mount Fuji. The park includes a variety of geographic features including natural hot springs, coastlines on the Pacific, mountainous areas, lakes, and more than 1,000 volcanic islands. Vegetation in the park ranges from species of mountainous trees to the subtropical vegetation of the Izu Islands.

Aogashima (青ヶ島) is a volcanic island to the south of Japan in northernmost Micronesia. It is the southernmost and most isolated inhabited island of the Izu Islands. The islands border the northeast Philippine Sea and lie north of the Ogasawara Islands. The island lies approximately 358 kilometres (222 mi) south of mainland Tokyo and 64 kilometres (40 mi) south of Hachijō-jima.

The island is administered as the village of Aogashima, which is subordinate to the Hachijō Subprefecture, which itself is governed by the City of Tokyo. The island has an area of 8.75 km (3.38 sq mi), and, as of 2014, its population is a mere 170 people. This means that the village of Aogashima has the smallest population of any municipality in Japan. Aogashima is also part of the Fuji-Hakone-Izu National Park.

Hachijō-kojima (Japanese: 八丈小島) is a small volcanic island of Japan in the Philippine Sea, approximately 287 kilometres (178 mi) south of Tokyo and 7.5 kilometres (4.7 mi) west of Hachijō-jima, in the northern Izu archipelago. Administratively, the island is within Hachijō, Tokyo, Japan. It has been uninhabited since 1969.