South of Chichijima the Bonin chain thins out, and then Hahajima, the mother island, rises out of the Pacific with its own scatter of small satellites around it. Mukōjima, the island that gives this point its name, is one of those satellites, a low spit of land in the Hahajima group that you look across a channel to see. Its name simply means the island on the other side, which is the sort of down-to-earth naming the islanders have given to everything in sight. Nearby are Anejima, Imōtojima and Meijima, elder sister, younger sister and niece.
Hahajima is the only inhabited island in this group, home to a few hundred people in two small villages, Okimura and Kitamura. The ferry that serves it from Chichijima takes about two hours, and most visitors make it a day or overnight trip by small boat after the long ferry from Tokyo. A narrow island road runs along the coast and up toward the hills, with views of the sea on both sides, and it is quiet, with little traffic, short climbs and the smell of salt and warm vegetation. The highest point, Chibusa-yama, wears cloud around its top much of the year.
The islands have been protected as part of the Ogasawara World Heritage Site since 2011, and the point of interest is the unusually isolated ecology. Species of plant, land snail and insect have developed here that exist nowhere else, and the area around Hahajima holds some of the best surviving native forest. The sea around the islet is bright blue, and divers and snorkellers on guided boats can find coral gardens and reef fish. In winter humpback whales pass the coast, and from some of the headlands you can watch them from land.
Landing on tiny islets such as this is restricted to protect nesting birds and fragile vegetation, so the sensible way to see it is on a boat tour from Hahajima's port. Fuel and basic supplies are available in the village, but nothing is plentiful, and everything arrives by ship. Typhoons in late summer and autumn can disrupt crossings, so give yourself spare days at either end and keep the plan loose.