Chichijima in the context of "Nanpō Islands"

The Bonin Islands, also known as the Ogasawara Islands (Japanese: 小笠原諸島), is a Japanese archipelago of over 30 subtropical and tropical islands located around 1,000 kilometers (620 mi) SSE of Tokyo and 1,600 kilometers (1,000 mi) northwest of Guam. The group as a whole has a total area of 84 square kilometers (32 sq mi) but only two of the islands are permanently inhabited, Chichijima and Hahajima. Together, their population was 2,560 as of 2021. Administratively, Tokyo's Ogasawara Subprefecture also includes the settlements on the Volcano Islands and the Self-Defense Force post on Iwo Jima. The seat of government is Chichijima.

Because of the Bonins' isolation, many of their animals and plants have undergone unique evolutionary processes. They have been referred to as the "Galápagos of the Orient" and were named a Natural World Heritage Site in 2011. When first reached during the early modern period, the islands were entirely uninhabited, although subsequent research has found evidence of some prehistoric habitation by Micronesians. Upon their repeated rediscoveries, the islands were largely ignored by the Spanish, Dutch, and isolationist Japanese until finally being claimed by a passing British captain in 1827. American, European, and Hawaiian colonists arrived from the Kingdom of Hawaii in 1830. Subsequently, Meiji Japan successfully colonized and reclaimed the islands in 1875, but Bonin Islanders' community continued up to World War II, when most islanders were forcibly relocated to Honshu. Following Japan's defeat, the U.S. Navy occupied the island, bulldozing existing Japanese homes and restricting resettlement until full control of the Bonins was returned to Japan in 1968. Ethnically, the island is now majority Japanese but remains unusually diverse, which is reflected in the local Creole language known as Bonin English. Improved transportation has made agriculture more profitable and encouraged tourism, but the development required for an airport remains a contentious local issue.

Hahajima, Haha Jima, or Haha-jima (母島; meaning Mother Island) is the second-largest island within the Bonin or Ogasawara Islands SSE of the Japanese Home Islands. The steeply-sloped island, which is about 21 km (8 sq mi) in area, has a population of 440. It is part of Ogasawara Village in Ogasawara Subprefecture, which is approximately 1,000 km (620 mi) south of Tokyo, Japan.

The highest peaks Hahajima are Chibusayama (lit. Breast Mountain), approximately 462 metres (1,516 ft), and Sakaigatake, 443 metres (1,453 ft). It is part of an archipelago that includes Chichijima approximately 50 km (31 mi) to the north and the nearby smaller islands such as Anejima and Imōtojima and Mukōjima. The group forms the Hahajima Rettō (母島列島; formerly the "Baily Group").

Ogasawara Subprefecture (小笠原支庁, Ogasawara-shichō) is a subprefecture of the Tokyo Metropolitan Government in Japan. The subprefecture covers the Bonin and Volcano Islands and three isolated islets (the "Ogasawara Archipelago") and is coterminous with the village of Ogasawara. The subprefecture covers 104.41 square kilometers (40.31 sq mi) and has a population of 2,930 in 2023. It maintains a main office on Chichijima and a branch office on Hahajima, the two permanent settlements in the islands. (The SDF base on Iwo Jima is supported separately, although still notionally part of the subprefecture and village's jurisdiction.)

The Bonin Islanders, also known as the Ogasawara Islanders or Ōbeikei tōmin (欧米系島民; lit. 'European–American Islanders') in Japanese, are a Euronesian ethnic group native to the Bonin Islands (or Ogasawara Islands). They are culturally and genetically distinct from other Japanese ethnic groups such as the Yamato, Ainu, and Ryukyuans as they are the modern-day descendants of a multitude of racial and ethnic groups including the Europeans, White Americans, Polynesians, and Kanaks who settled Hahajima and Chichijima in the 19th century.