Kazuo Sakai is a Japanese animator and anime director.
Japan has been invaded and conquered by the Britannian Empire. Japan is now known as Area 11 and its citizens known as Elevens. The Britannian Empire takes away Japan's autonomous power and imposes its rule through the use of Knightmares. The Empire's rule has never faltered, but cracks have begun to show...
In the future — in a world mostly submerged under water — the 19-year-old Sumeragi Aika goes to college while training as an agent by assisting in Aida Gozo's salvaging business.
The story takes place in the year 1614. Two ninja clans, Tsubagakure of the Iga and Manjidani of Kouga, battle each other to determine which grandson of Tokugawa Ieyasu will become the next shogun. The deadly competition between 10 elite ninja from each clan unleashes a centuries-old hatred that threatens to destroy all hope for peace between them.