Kuribayashi was the actual commander of the Iwo Jima garrison. His background and unconventional defense strategy depicted in the film are historically accurate.

Nishi was a real, famous figure who died on Iwo Jima. His aristocratic background, fame, and reported interactions (like with the wounded American) are based on historical accounts.

Saigo is a fictional character created to represent the perspective of an ordinary, unwilling conscript, contrasting with the professional soldiers and fanatics.

Shimizu is fictional, representing soldiers with different backgrounds and perhaps disillusionment. His backstory highlights the harshness of the Kempeitai.

Ito likely represents or is a composite of younger, fiercely nationalistic officers who clashed with Kuribayashi's pragmatic strategy and preferred traditional "banzai" attacks.

Oiso served as Kuribayashi's chief of staff on Iwo Jima.

Kuribayashi rejected traditional beach defense and ordered the construction of extensive underground fortifications, focusing on attrition warfare.

The Japanese forces built miles of complex tunnels and bunkers on Iwo Jima, which formed the core of their defensive strategy depicted accurately in the film.

The Japanese garrison suffered from critical shortages, particularly fresh water, leading to widespread illness (like dysentery) and weakening the troops.

While based on real letters found after the war (compiled by Tsuyuko Yoshida), the specific letters read in the film are dramatized representations, not direct transcriptions.

Kuribayashi faced resistance from subordinates who favored suicidal "banzai" charges over his orders for a prolonged defense, reflecting real tensions in the Japanese military.

This incident is based on accounts suggesting Nishi treated a captured/wounded American kindly, possibly involving a letter. Details vary, but the event's essence is plausible.

Mass suicides and pressure to commit suicide to avoid capture were common among Japanese forces, especially as defeat became inevitable.

There were instances where Japanese officers or zealous soldiers killed comrades who tried to surrender or appeared defeatist, as depicted with Shimizu.

Kuribayashi led a final, disorganized attack. The exact circumstances of his death remain unknown; suicide, dying in combat, or ritual beheading are all possibilities reflected uncertainly in the film.

Saigo is fictional, so this specific event didn't happen. The letters were discovered years later by Japanese authorities clearing the island, not buried by a surviving soldier.

The Japanese garrison was effectively cut off and received almost no support from the Imperial Navy or Air Force during the main battle.

The film effectively portrays the horrific conditions, intense close-quarters combat within tunnels, and the sheer desperation of the Japanese defense.

The film's strength is portraying the Japanese soldiers not as stereotypes but as individuals with families, fears, and differing motivations, based on their letters.

While Shimizu is fictional, the portrayal reflects the fear and mistrust associated with the Kempeitai within the regular army.

Filmed primarily in Iceland and California, the film effectively recreates the distinctive barren, volcanic landscape of Iwo Jima, including Mount Suribachi.

The claustrophobic, dark, and extensive underground fortifications central to the battle are realistically depicted, showing the conditions soldiers lived and fought in.

The uniforms, helmets (often covered), Arisaka rifles, grenades, and other gear used by the Japanese soldiers appear authentic for the period.

Though seen from the Japanese perspective, the film conveys the overwhelming naval bombardment, air attacks, and use of flamethrowers by US forces against the bunkers.

The film accurately portrays the suffering caused by heat, lack of water, poor sanitation, disease, and constant fear within the besieged tunnels.

The sounds of constant shelling, gunfire, and explosions effectively create an immersive and harrowing atmosphere of the intense battle.

The film is correctly set during the February-March 1945 battle, reflecting the desperate situation of Japan late in the war.

The film successfully captures the pervasive sense of fighting a hopeless battle, mixed with the soldiers' sense of duty and varying degrees of fanaticism.