"No-one takes responsibility," says Shim Jin-tae, an 83-year-old survivor. "Not the country that dropped the bomb. Not the country that failed to protect us. America never apologised. Japan pretends not to know. Korea is no better. They just pass the blame - and we're left alone."
Korea had been a Japanese colony for 35 years when the bomb was dropped. An estimated 140,000 Koreans were living in Hiroshima at the time - many having moved there due to forced labour mobilisation, or to survive under colonial exploitation.
“Korean workers had to clean up the dead," Mr Shim, the director of the Hapcheon branch of the Korean Atomic Bomb Victims Association, tells BBC Korean. "At first they used stretchers, but there were too many bodies. Eventually, they used dustpans to gather corpses and burned them in schoolyards.
According to the Korean Atomic Bomb Victims Association, the Korean fatality rate was 57.1%, compared to the overall rate of about 33.7%. About 70,000 Koreans were exposed to the bomb. By year's end, some 40,000 had died.
Ms Ichiba notes that Japanese textbooks still omit the history of Korea's colonial past - as well as its atomic bomb victims – saying that "this invisibility only deepens the injustice". This adds to what many view as a broader lack of accountability for Japan's colonial legacy.
"Memory matters more than compensation," he says. "Our bodies remember what we went through… If we forget, it'll happen again. And someday, there'll be no one left to tell the story."