|Native name: Akujikishima|
|Area||7.95 km2 (3.07 sq mi)|
|Population||0 (as of October 5, 1986)|
Rokkenjima (六軒島, Rokuken Island, lit. "Six House Island") is a fictional island located just off the coast of the Izu Peninsula of Japan. Rokkenjima serves as the primary location in which Umineko no Naku Koro ni takes place. Rokkenjima is roughly 10km (~6.2mi) around and is mostly covered by dense forest. There are two mansions on the island: the Ushiromiya family's main mansion and the much smaller Kuwadorian. Rokkenjima was once called Azukishima (a mispronunciation of Akujikishima), and was said to have been the home to many evil spirits until a traveling monk expelled them from the island by way of a shrine. The patriarch of the Ushiromiya family, Kinzo Ushiromiya, resides on the island with his eldest son Krauss and Krauss's immediate family. The rest of the Ushiromiya family visits the island once a year for an annual family meeting. Umineko no Naku Koro ni focuses on the events of the 1986 family conference which became known as the Rokkenjima massacre.
Rokkenjima was used in World War II as a military base for the Japanese army. It was meant to serve as a launching point for the navy's Kaiten torpedoes, but was never supplied with them due to the nation's poor financial state, and eventually forgotten by the military command. In 1944, Kinzo Ushiromiya was stationed on the island when a submarine containing soldiers from the Italian Social Republic docked, having suffered casualties to a chlorine gas leak. It is during this time where he met Beatrice Castiglioni and uncovered ten tons of gold. A gunfight eventually broke out between the Japanese and Italians over the possession of the gold, leaving Kinzo and Beatrice as the only survivors.
The island was then purchased by Kinzo from the Tokyo metropolis utilizing his connections with the GHQ. It was acquired under the pretext of establishing a military base, but then converted into Kinzo's own personal island. The island was then developed, with the mansion constructed in 1952. Kinzo's wife and children moved onto the island with him, and the residence of the island eventually shifted to Krauss's family. Despite the island's residential use, there still exist 900 tons of explosives beneath the island, left over from the former World War II military base.
After the Rokkenjima massacre, the island was repossessed by the Tokyo Metropolis and sealed off from the public.