Atragon

Atragon (aka Kaitei Gunkan, or Undersea Warship) is a 1963 tokusatsu film from the producers and crew of Godzilla.

The lost kingdom of Mu, which sank beneath the sea over twelve thousand years ago, launches an assault to make the upper world their domain again. With an array of weaponry, the Mu Kingdom wages a war with the surface dwellers, who counter with the super-scientific battleship Gotengo.

As the Gotengo attempts to defeat the Mu Kingdom in their own underwater base, the Mu unleash the legendary sea dragon Manda against the humans.

This movie introduces Manda to the Toho universe, who was later incorporated into the Godzilla universe. It also marks the first appearance of the Gotengo, which became one of Toho's signature military battle vehicles. Gotengo appears 2004's Godzilla: Final Wars, which recreates the battle between the Gotengo and Manda from this film.

Tropes that apply to Atragon include:

 * Cool Ship:
 * The Gotengo.
 * Subverted with the Red Satan, supposed to be a super-advanced submarine but is destroyed after one encounter when is pursues a Mu submarine past crush depth.
 * Doomsday Device: Mu's seismic generator.
 * The Stoic: Captain Jinguji, played by the master of stoics, Jun Tazaki.
 * Yamato Nadeshiko: The Empress of Mu.