Japan’s “sea” turtles are primarily green turtles (Chelonia mydas), which nest in the Nansei and Nanpō islands, hawksbill turtles (Eretmochelys imbricata) that nest in the Ryū-Kyū archipelago and also loggerhead turtles (Caretta caretta) which nest in Honshū, Shikoku, Kyūshū, and the Nansei Islands.
Other turtles such as the leatherback (Dermochelys coriacea) and Olive ridley (Lepidochelys olivacea) turtles do not nest in Japan, but often cruise offshore in Japanese waters.
Southern Japan is thought to be the only loggerhead turtle breeding ground in the North Pacific.
Green and hawksbill turtle populations not only breed on Japanese coasts but also stay around, growing to maturity in the habitat provided by Japanese waters.
Shikine-jima, Hachijō-jima and the other Izu islands are all famous for their turtle populations, including green turtles (Chelonia mydas) and sometimes hawksbill turtles (Eretmochelys imbricata)
Shikine-jima also has a spot where turtles like to relax in warmth of the hot springs that flow into the sea, a kind of reptilian alternative to Nagano’s bathing “snow monkey”
From February to August the Ogasawara/Bonin Islands are said to become one of the biggest nesting ground of green turtles in Japan.
Loggerhead turtle (Caretta caretta) nesting events take place in Tokushima Prefecture’s Mugi area, from the end of June to July.
The three major types of turtles nest and evovle in the greater Kyūshū area. Turtle are very common especially in the Satsunan Islands (Kagoshima Pref.), notably on the islands of Yakushima, Okinoerabujima and Yoron but also in Oita Prefecture’s Hazako, and Miyazaki Prefecture’s Nobeoka, the beaches of which are all seasonal turtle nesting sites (usually end of May to end of July).
The Amami islands’ Tokunoshima, is home to a famous green turtle with a mountain-shaped shell nicknamed Yama-chan (Yama is mountain in Japanese), that has been entertaining divers in the shallows for over 10 years.
Japan’s 3 main types of turtles can be reliably spotted on most of islands of the Okinawa region, which is home to large populations of hawksbill and green turtles (Eretmochelys imbricata and Chelonia mydas).
Turtles are particularly frequent on Miyako and the Yaeyama islands (Iriomote, Kuro, Ishigaki…)
They are also frequently seen in the Kerama islands, on sites such as Gishippu, which is home to healthy populations of hawksbill and green turtles (Eretmochelys imbricata and Chelonia mydas)
Near Okinawa Main Island, Kudaka Island (south east of Naha) and the Chibishi Islands (west of Naha) are famous for their green turtle populations, as well as seasonal nesting of loggerhead turtles (Caretta caretta).
Kume island, 100 km west of Okinawa Main Island, has a site called Turtle Paradise (“Kame Paradise”) where it is sometimes possible to see 50 or more turtles resting on the reef.