Gate Season 2: Jieitai Kanoumi nite, Kaku Tatakaeri

With the Gate open again, Japan's Self-Defense Forces continue surveying the Special Region and building relations with its nations. Maritime officer Goro Edajima and his subordinate Hajime Tokushima are carrying out diplomatic and exploratory missions when they receive an urgent assignment: rescue an American journalist kidnapped on an island in the Blue Sea.

The pair board the submarine Kitashio and sail into an ocean belonging to another world, only to find the Blue Sea caught in a struggle among island nations, pirates, and rival powers. A rescue operation becomes a test of how Japan can act in a region where advanced technology alone cannot solve the political and military conflicts waiting beyond the shore.