Takashi Kinoshita, 73, lived most of his adulthood with a secret that until recently he wouldn't dare divulge even to his children: he was nearly illiterate.

As a child, Kinoshita grew up at a time when Japan was still in the grip of postwar poverty. He gave up compulsory education and started looking for work at age 13. Even as the nation went on to become an economic superpower, the Osaka-based steelworker remained cut off from mainstream society. His work, he said, seldom required any writing.

"I was able to read to some extent. But I could barely write," said Kinoshita, who is now retired. "So every time I sensed somebody was about to ask me to write something, I'd duck out to spare myself embarrassment."