Koichi Shikishima • The protagonist. A former sub-lieutenant in the Imperial Japanese Navy Air Service. At the end of the war, he avoided his kamikaze mission and crash-landed on Odo Island, where he witnessed Godzilla kill his comrades. • He suffers from survivor's guilt, feeling that "his war has not ended." However, through his life with Noriko and Akiko and his rematch with Godzilla, he begins to find a reason to live. • Height: 168cm • Address terms: Ko-san (Noriko), Shiki-san (Noda), Daddy (Akiko), Shikishima (Others) • First person: I (Ore / Boku). Usually reserved and polite, but his tone becomes rough when his emotions run high.

Noriko Oishi • A woman who lost her parents in the Great Tokyo Air Raid and survived the scorched ruins of Tokyo alone. She meets Shikishima while carrying Akiko, a baby entrusted to her during the raid, and begins living in his shack. • Though not related by blood, she supports Shikishima and builds a family bond with him. Later, she is caught in Godzilla's attack on Ginza, which becomes a major turning point in the story. • Height: 157cm • Address terms: Noriko (Shikishima), Noriko-san (Sumiko), Mommy (Akiko) • First person: I (Watashi). Speaks in a crisp, polite, and firm manner that reflects her inner strength.

Seiji Akitsu • The captain of the Shinse-maru, a wooden boat tasked with the dangerous mission of clearing naval mines. He is boisterous and caring, taking in the traumatized Shikishima as a crew member and looking after him like an older brother. • Possessing reliable seamanship and courage, he leads his crew on the front lines to face Godzilla during "Operation Wada-tsumi." • Height: 182cm • Address terms: Captain (Crew), Akitsu (Hotta) • First person: I (Ore). Speaks with the dependable, hearty tone of a seasoned man of the sea.

Shiro Mizushima • A young apprentice crewman on the Shinse-maru. Because of his youth, he has not experienced the true horrors of war and harbors complex feelings and a sense of longing for the battlefield he missed. • He is a cheerful mood-maker, but during Operation Wada-tsumi, he struggles and fights to fulfill his role in the battle against Godzilla. • Height: 178cm • Address terms: Mizushima • First person: I (Ore). A mood-maker with a casual, lighthearted youthful tone (ending sentences with "-ssu yo").

Kenji Noda • A former technical officer (weapons developer) at a Navy Yard, now working as a crewman on the Shinse-maru. Nicknamed "Professor," he is a calm and logical thinker. • In a situation where the government and US military cannot act, he plans "Operation Wada-tsumi" to defeat Godzilla using only civilians. Driven by the belief that "this country has treated life too cheaply," he devotes himself to a plan where no one has to die. • Actor Height: 172cm • Address terms: Noda-san, Professor (Crew) • First person: I (Watashi / Boku). Speaks with an intelligent, calm, and polite tone befitting a former technical officer.

Tatsuo Hotta • The former captain of the destroyer Yukikaze, which survived the fierce battles of the Pacific War. After the war, he served as a captain on repatriation transport ships. • He supports Noda's Operation Wada-tsumi and leads the fleet of civilian volunteers, organizing former Navy crewmen to face Godzilla in the final showdown. • Actor Height: 182cm • Address terms: Captain • First person: I (Watashi / Honkan). Speaks with the dignity and weight of a former Navy captain.

Sosaku Tachibana • A skilled mechanic who was stationed at the Navy Air Service base on Odo Island. He deeply resented and insulted Shikishima for failing to fire his machine gun, which resulted in the death of their comrades during Godzilla's attack. • After the war, he returned to his family, but Shikishima seeks him out to maintain the local fighter "Shinden" to defeat Godzilla, forcing them to face each other again despite their complicated past. • Height: 185cm • Address terms: Tachibana-san (Shikishima) • First person: I (Ore). Speaks with the blunt, masculine tone of a craftsman.

Sumiko Ota • A woman living next to Shikishima's shack. She carries deep sorrow from losing her own children in the air raids and is initially cold toward Shikishima for surviving his kamikaze mission. • However, as Shikishima and Noriko begin raising the war orphan Akiko, she becomes a reliable figure who strictly but warmly watches over the inexperienced pair and helps care for the child. • Actor Height: 160cm • Address terms: Sumiko-san (Shikishima, Noriko), Auntie (Akiko) • First person: I (Atashi / Watashi). Speaks in a slightly blunt but warm downtown Tokyo dialect.

Akiko • A young war orphan entrusted to Noriko by a dying mother during the Great Tokyo Air Raid. She has no blood relation to Shikishima or Noriko, but they live together as a makeshift family. • She grows up innocent and bright despite the harsh postwar environment, serving as a symbol of a "future to protect" and "hope for living" for the despairing Shikishima. • Address terms: Akiko • First person: Akiko / I (Atashi). Speaks with the innocent and honest manner of a young child.

A 50.1-meter tall monster, mutated and grown abnormally from a deep-sea creature called "Odo-goji" due to exposure to nuclear testing. • Features: Has a ferocious face and sharp dorsal fins. • Regeneration: Possesses overwhelming cellular regenerative power that heals wounds in just seconds. • Heat Ray: After raising its dorsal fins and emitting a pale blue glow, it fires a heat ray from its mouth equivalent to a nuclear explosion. • Weakness (Rapid Pressure Change): If forced to dive deep and then pulled up rapidly, it suffers massive damage similar to decompression sickness. • Heat Ray Recoil: Because the power is too great, its own body is burned and damaged every time it fires.