A captain seals his crew inside a nuclear submarine and declares independence from every nation on Earth. What starts as a political hostage crisis becomes a cold war chess match where every depth charge is a negotiation, every sonar ping is an argument about sovereignty. The military hardware actually matters here, the technical details aren't window dressing, they're the plot itself. Built for people who want their war stories grounded in the real friction between nations, not anime melodrama. Three episodes, impossible to find, and it still understands submarine warfare better than shows made thirty years later.

During the Cold War, Japan's Maritime Self-Defense Force and the United States Navy build a nuclear submarine together. On the vessel's first voyage, its captain proclaims that the submarine is now a sovereign nation of its own, named Yamato. This three-episode OVA from 1995 is a drama built around that bold declaration and the questions of loyalty and power it raises at sea.