This is the second instalment in a series.
On the evening of Aug. 11, 1945, two days after the atomic bomb was dropped on Nagasaki, Reiko Ono's brother Tsugiyuki returned home uninjured.
"You're not a ghost, are you?" then 10-year-old Ono asked jokingly, touching Tsugiyuki, 15, on the shoulder. The family had thought he was dead.
Tsugiyuki saw the light emitted by the atomic bomb from Chinzei Gakuin Middle School, about 500 meters from the hypocenter of the blast. He ran in to an air-raid shelter next to the school building and was buried alive. He was rescued while still unconscious and taken to a hospital. Tsugiyuki explained all this with a smile as he ate some pumpkin for dinner.
However, the next morning, Tsugiyuki couldn't get up, saying, "I feel weak."
His body temperature soured to 42 C, his hair fell out and he repeatedly vomited up blackish clumps of blood. On Aug. 24, he died.
Ono's cousin was injured, with about 250 glass pieces stuck in one arm, yet survived the blast. Thinking "my brother wasn't hurt at all," Ono was struck with mindless fear.
In addition to the bomb blast and heat wave, victims suffered due to radiation, which inflicted damage at a cellular level.
Many people within several kilometers of the hypocenter reported such symptoms as hair loss, purple spots, high fever and hemorrhage.
For some, there was nothing to be done before they died. These were acute symptoms of radiation exposure.
When hibakusha (atomic bomb survivors) need treatment due to malignant tumours, leukemia, cardiac infarcts and other ailments, they may be officially recognised as having radiation sickness.
This entitles them to a special monthly medical allowance of about ¥140,000 (S$1,554), which is provided by the government apart from medical costs.
However, there are certain requirements for receiving the allowance, such as how far they were from Ground Zero when they were exposed.
There were a total of 183,519 holders of special hibakusha health-care certificates for the bombings in Hiroshima and Nagasaki as of the end of March, but only 4.8 per cent of them, or 8,749, were recognised as having radiation sickness.
Ono, now 80, lives in Matsudo, Chiba Prefecture. She talks to primary and middle school students about her experience on more than 10 occasions each year.
Ono always tells the children: "One could die even without any injuries. That's the horror of the atomic bomb."
Poverty and discrimination
The effects of radiation have haunted the lives of atomic bomb survivors.
"Just as I expected." So thought a 72-year-old woman in Kure, Hiroshima Prefecture, when she was diagnosed with malignant lymphoma at a hospital nine years ago.
Her older brother and sister, both hibakusha, died from cancer after the war. The woman was the youngest of seven siblings, a boy and six girls. She experienced the bombing when she was 2 years old, in Ushita-Honmachi, now Higashi Ward, in the city of Hiroshima, about 2.5 kilometers from the blast centre.
Looking for her brother and sisters, she entered the central area of the city while being carried by her mother for several days.
Her mother died eight months later, probably as a result of that exposure, while her father also died from a disease. The woman was adopted by another family, but three years later, her brother, who was also exposed to the Nagasaki bombing and had reached the age of 17, took her back.
"I'll protect you no matter what," he said. He worked at a stone dealer's shop to scratch out a living for himself and his three sisters in a 4.5-tatami mat shed. When the woman got married at age 21, her brother told her: "You may develop a disease in the future. If you're divorced for that, I'll take care of you."
In 1999, when her brother was 68 years old, he was found to have lung cancer. His doctor said, "People can develop lung cancer even if they are not exposed to radiation," but five years later, bone cancer was also found.
"Why should I suffer such punishment? Because of the war?" her brother complained. He died a month and a half later.
The woman was recognised as having radiation sickness in 2009. However, a neighbour told her, "You're lucky to be a recipient" of the special monthly medical allowance. These words were very painful and in May this year, she refused to accept the money.
Ono wants people to know about her suffering but does not want them to know that she is hibakusha. This spring, a shadow was also found in her pancreas.
"My family was devastated, and I suffered from poverty and discrimination. My life is bound to the atomic bomb. I want to be freed from this," she said in a trembling voice.