My mother and her siblings were fortunate. The way that poor family lived reminded me of how they lived, in a cave shelter dug out of volcanic sand by her grandfather, during the war. Afterwards, their neighborhood had survived the firebombing relatively intact and they were able to just move back. A lot of families did not have that luxury and it doesn’t surprise me that some may have taken longer, if ever, to bounce back.
What happened to Masako was pretty typical how certain social strata were treated. I don’t think that if she came from a ‘good’, ie, middle-class and/or ethnically pure, family she would not have had to work in a factory at her age. Having known plenty of ladies like her, she must have been a lovely girl and a real survivor.