Genbu

In the Land of Lightning, there is an unnamed, remote island that serves as a training ground for Kumogakure ninja. It is considered to be the equivalent of Konoha's Forest of Death. Despite being described by the Great Toad Sage as a paradise, it is anything but, with signs of death and battle everywhere and large, ferocious animals populating the island. The Falls of Truth can also be found on the island. The island is protected by a giant squid, which attacks anything that approaches, and a high-level barrier technique.

A and Killer Bee trained on the island when they were younger. While there, Bee tamed and befriended all the animals on the island. He now has a vacation home there. When the Fourth Great Shinobi World War begins, the Shinobi Alliance sends Bee and Naruto Uzumaki, the only two remaining jinchūriki, to the island to be hidden from Akatsuki. A number of Konoha ninja accompany Naruto as extra protection, including Might Guy, Aoba Yamashiro and Yamato, with Motoi serves as a guide for all of them.

Trivia

 * Due to the apes and the very obscure settings on the island, it might be a reference to Skull Island from the 1933 film King Kong. Killer Bee also affectionately calls an ape "King", a reference to the film's title character.