The Okinawa rail is a species of bird in the rail family, Rallidae. It is endemic to Okinawa Island in Japan where it is known as the Yanbaru kuina . Its existence was only confirmed in 1978 and it was formally described in 1981 although unidentified rails had been recorded on the island since at least 1973 and local stories of a bird known as the agachi kumira may refer to this species.

Okinawa Island , officially Okinawa Main Island , is the largest of the Okinawa Islands and the Ryukyu (Nansei) Islands of Japan in the Kyushu region. It is the smallest and least populated of the five main islands of Japan. The island is approximately 106 kilometres (66 mi) long, an average 11 kilometres (7 mi) wide, and has an area of 1,206.98 square kilometers (466.02 sq mi). It is roughly 640 kilometres south of the main island of Kyushu and the rest of Japan. It is 500 km northeast of Taiwan. The total population of Okinawa Island is 1,384,762. The greater Naha area has roughly 800,000 residents, while the city itself has about 320,000 people. Naha is the seat of Okinawa Prefecture on the southwestern part of Okinawa Island. Okinawa has a humid subtropical climate.