So, I read up a bit on Barefoot Gen earlier today and then looked into the author. I had no prior knowledge of the effects of the bomb itself or of the radiation from it, but I did remember reading that the manga was based on the author’s real life experience. I wanted to look into it a bit more after reading your post to see how loosely.
I found this interview with the author which I was initially going to skim but ended up reading most of it. I’m gonna quote some of your post and follow it up with some quotes from the interview of the author describing his experience.
Indented quotes are from: Keiji Nakazawa Interview in The Comics Journal #256 (October 2003).
Link: http://www.tcj.com/keiji-nakazawa-interview/
“Gen’s survival truly made me upset, not just by surviving being vaporized, but especially after contracting acute radiation poisoning.“
“I was standing right in front of the [school] gate, and the lady was standing about a meter in front of me. … Then, just at that moment, there was a huge flash. It seemed to rush at me. I remember the center was pure white, with blue-white around it and orange-red around that. I saw that flash for an instant, and after that I don’t remember anything.
The next thing I remember, it was pitch dark. It seemed like night. But a moment ago, there had been blue sky overhead. I felt something jabbed in my cheek, a nail — I still have the scar, see? I wondered what had happened… . I saw the lady I’d just been talking to, but now she was lying out in the street. Her hair was all burned, her face and skin were black, and she was staring straight at me.“
“Other incongruities include the “ghost” figures he sees immediately after the bomb, …”
“There were throngs of people walking silently along, like a parade of ghosts. Their skin was all in strips. The heat from the A-bomb reaches around 5,000 or 6,000 degrees, you know; it melts the skin right off you in an instant. But human skin is pretty amazing stuff. It strips right off you all the way down to your fingernails, and just hangs there. So people were walking along with their hands out in front of them, the skin from their arms dragging on the ground. Just like a bunch of ghosts.“
“… as well as that hauntingly graphic scene where only choice parts of people are incinerated.”
“Another thing I noticed was that people wearing white clothing had those clothes on intact. But the rest of them was completely burned. Later I learned that the heat of the blast behaved like light hitting a mirror. It reflected off white clothes but was absorbed by dark clothes. Unfortunately, most people at this point in the war were in the habit of wearing dark clothes so they wouldn’t be visible to enemy planes at night.“
“… but the reality is that people close enough to the epicenter (close enough to have their eyeballs boil out of their skulls) would have been vaporized. “
“When the blast from the bomb hit people in the face, their eyeballs would pop out and dangle from their sockets. So people were staggering along supporting their eyeballs in their hands.”
Ore wa Mita (I Saw It) is supposedly an autobiography by Nakazawa and I definitely want to read it. The page that had the interview had some pages from it. Even those standalone pages hurt to read. Sometimes reality is stranger (and more cruel) than fiction.