Godzilla Minus One

In 1945, near the end of World War II, kamikaze pilot Kōichi Shikishima lands his Mitsubishi A6M Zero for repairs at the Japanese base on Odo Island. Lead mechanic Sōsaku Tachibana deduces that Kōichi is feigning technical issues to flee from his duty. That night, Godzilla, a large dinosaur-like creature, attacks the garrison. Tachibana tells Kōichi to fire at the monster with his plane's cannons, but he panics, fails to shoot, and is knocked unconscious. When he awakes the following day, he finds that the only other survivor is Tachibana, who is furious at him for failing to act.

The war now over, Kōichi returns home to find that his parents were killed in the bombing of Tokyo. Plagued by survivor's guilt, he begins supporting a woman, Noriko Ōishi, whose parents also died in the bombing, and an orphaned baby, Akiko, whom Noriko rescued. He finds employment aboard a minesweeper tasked with disposing of wartime naval mines. Meanwhile, Godzilla is mutated and empowered by the United States' nuclear tests at Bikini Atoll; it sinks the USS Redfish and destroys several other ships en route to Japan. Owing to tensions with the Soviet Union, the U.S. offers no help save for a few decommissioned Imperial Japanese Navy (IJN) vessels approved by General Douglas MacArthur. The Japanese government, concerned about inducing panic so soon after the war's end, does not notify the public about the danger.

In May 1947, Kōichi and his minesweeper crew travel to the Ogasawara Islands and are tasked with stalling Godzilla's approach to Japan. They release a mine into Godzilla's mouth and detonate it, causing significant damage, but Godzilla quickly regenerates. The heavy cruiser Takao then engages Godzilla, but is destroyed when the monster unleashes its heat ray. After returning to Tokyo, Kōichi opens up to Noriko about his encounters with Godzilla. Days later, Godzilla makes landfall in Japan and attacks Ginza, where Noriko works. She narrowly survives the initial attack and reunites with Kōichi. Enraged by tank fire, Godzilla obliterates much of the district with its heat ray, killing tens of thousands. Noriko pushes Kōichi to safety, but is caught in the blast herself. A devastated Kōichi mourns her along with his fellow crewmates, vowing revenge.

Former naval engineer Kenji Noda, a crewmate, becomes frustrated by the government's inaction. He devises a plan to destroy Godzilla by luring it out to Sagami Bay before surrounding it with Freon tanks and rupturing them, sinking the monster, and letting the resultant water pressure crush it. Should the plan fail, balloons will be inflated under Godzilla to force it back up, killing it through explosive decompression. To enact his plan, Noda has recruited navy veterans to crew disarmed IJN destroyers. Kōichi recruits Tachibana to repair a broken-down Kyushu J7W Shinden fighter. He plans to kill Godzilla in a suicide attack by flying into its mouth and detonating explosive charges on board. He leaves Akiko in the care of his neighbor, Sumiko, before Godzilla resurfaces.

As Kōichi lures Godzilla to the trap set by two destroyers, Sumiko receives a telegram intended for Kōichi. Godzilla survives the initial plunge and then breaks free before being forced back up, sustaining serious but nonfatal injuries from the resultant decompression-induced barotrauma. With the help of a fleet of tugboats organized by Mizushima, another crewmate from the minesweeper, the ships haul Godzilla to the surface. Enraged, Godzilla prepares to destroy all the vessels with its heat ray, but Kōichi crashes the plane into Godzilla's mouth and destroys its head, causing the energy of the heat ray to tear its body apart. Having worried about his suicidal inclinations, the crew celebrates as Kōichi ejects before the explosion and parachutes to safety, using an ejection seat that Tachibana installed in the Shinden; despite agreeing to work on the Shinden on the understanding that Kōichi would kill himself to atone for his failure on Odo Island, Tachibana eventually implored him to let go of his guilt and continue living.

Upon returning home, Sumiko gives Kōichi the telegram, which leads him to a hospital where he reunites with Noriko, who survived the destruction but has a black bruise creeping up her neck. Meanwhile, a chunk of Godzilla's flesh begins to regenerate as it sinks deeper into the ocean.