"My father required me to memorize the Constitution, particularly the equal-protection Article 14, by posting it on the wall," said Nakayama, 69, who was born into a poor family in a socially disadvantaged "buraku" area of Fukuoka Prefecture.

His father was involved in human-rights activism while working as a cobbler, and his mother collected secondhand goods for almost 40 years to support the family.

"We had only limited jobs, such as collection of waste materials and construction work, and I myself faced various discrimination," he said. "But my father expected me to overcome the situation."