Plot
A young girl named Suzu lives in a seaside town called Eba near Hiroshima. One day, Suzu paints a picture for her classmate, Tetsu, as he stares at the sea and laments the death of his brother, who drowned during his service as a sailor. In 1943, 18-year-old Suzu marries a young military clerk named Shusaku, whom she had once met as a child, and joins his family in Kure, a large naval port city 15 miles away from Hiroshima. As she adjusts to her new life, the threat of the Pacific War begins to encroach on the townspeople.
Suzu and Shusaku's family house is located on a hillside overlooking the town and with a view of the Combined Fleet in the harbor. Suzu's sister-in-law Keiko and niece Harumi occasionally stay at the house. As food shortages become commonplace, the government implements food rationing. Warning and evacuation preparations against United States air raids begin. Suzu, as a housewife in a Tonarigumi, takes turns overseeing food distribution, attends training against air raids, and other wartime preparations.
In December 1944, Tetsu, now a sailor in the Imperial Navy, visits Suzu. Understanding that it might be Suzu's last chance to see Tetsu alive, Shusaku leaves them alone to talk. Though he confessed his love for her, Suzu told him she loved her husband more than anything. The next spring, Shusaku is drafted by the Navy and quartered with troops in Otake City, 40 miles away.
In 1945, the Americans begin air raids on the Japanese mainland; in Kure, US Navy aircraft bomb the port. In addition to the death of her brother Yōichi, Suzu loses her right hand and Harumi is killed when a time-delayed bomb detonates close to them. After becoming depressed, Suzu decides to return to the safety of her hometown but her departure is delayed due to a doctor's appointment. That morning, Suzu and Keiko notice a bizarre light, followed by a sudden quake. The radio doesn't work and then the family sees a towering cloud in the direction of Hiroshima City. They soon learn that a new, devastating bomb has fallen on Hiroshima, killing countless citizens. For a while, Suzu is unable to get information about her hometown.
A few days later, in a radio address, the Emperor of Japan announces the end of the War. Suzu, having grown accustomed to the single-minded focus of keeping the family alive, is forced to accept the reality of her losses and falls into despair. American forces then arrive and occupy Kure, providing food to the local population. Suzu visits her grandmother Ito's family house in Kusatsu, a rural town to the west of Hiroshima and out of the affected area, to see her sister Sumi, the only survivor of Suzu's family. Sumi informs her of the fate of their parents: their mother had left for supplies and is presumed to have been killed instantly by the bomb's initial blast and shock wave while their father died a few months later after falling ill and succumbing to possible radiation poisoning. Sumi herself has fallen seriously ill from the radiation. Shusaku returns and reunites with Suzu. They come across an orphaned girl and adopt her. Suzu regains her passion for life slowly, with the courage and affection of her friends and family. As the credits roll, their adopted daughter is shown growing up in the Hojo residence, sewing clothes, aided by Suzu in post-war Japan.