Satoshi Kamata recalled a serial killer in the late 1960s when he heard news about a stabbing spree in which a 25-year-old temporary worker at an auto assembly factory killed seven people and injured 10 others in Tokyo's Akihabara district last June.
     ''I thought that Norio Nagayama had emerged again after 40 years,'' Kamata, a 70-year-old freelance journalist, said, referring to the serial killer who shot four people dead in 1968 at the age of 19 and later wrote a number of influential books behind bars. He was hung in August 1997.
     Forty years have passed since Nagayama was arrested April 7, 1969. But some documents throwing light on his prison life, such as hundreds of letters he received from prominent as well as unknown people including Kamata, still remain.
     The letters, stored at his supporter's home in Kashiwa, Chiba Prefecture, indicate how the so-called ''Nagayama Incident'' sent shock waves through Japanese society as it emerged from the postwar high economic growth era, when huge numbers of junior high school graduates like Nagayama rushed to Tokyo and other big cities from rural areas in search of jobs.
     Such teenagers were hailed as ''golden eggs,'' but most of them were from poor backgrounds like Nagayama while the Akihabara killer struck in the current era of economic stagnation.
     Born into extreme poverty in Abashiri, Hokkaido, with his father dying on a roadside and his mother abandoning him in a bleak house in the middle of a frigid winter, Nagayama became convinced after turning to study following his incarceration that poverty and ignorance led him to commit his crimes.
     His family eventually moved to Aomori Prefecture, from where he left for the capital at the age of 15. He stole the gun and bullets he used for the murders from a residence in the U.S. base in Yokosuka, Kanagawa Prefecture.
     Based on an account of the poverty surrounding him, his best-selling autobiographical work ''Tears of Ignorance,'' subtitled ''To Junior High School Graduates, the Golden Eggs,'' was published in 1971.
     ''I thought I could understand his message as I was also a young man who came up to Tokyo from a poor rural area in Aomori Prefecture like Nagayama,'' said Kamata, who himself took on menial work for three years before entering college. ''I considered his crimes my own issue and an issue of this society.''
     While Nagayama was initially sentenced to death at a lower court in 1979, the Tokyo High Court commuted the ruling in 1981, saying, ''The government should have rescued the defendant from his poor surroundings. It would be unfair to ignore the lack of proper welfare policies and lay all the responsibility on him.''
     But the Supreme Court ordered a retrial, which eventually led the high court to reverse its earlier decision and sentence him to death. His sentence was finalized in 1990.
     Munesuke Mita, a prominent sociologist, is another person who wrote to Nagayama.
     He had just started an academic career at the University of Tokyo when he sent a letter to Nagayama in April 1973 to seek Nagayama's comments on his dissertation on city theory, in which he analyzed the struggles of a small-town boy who arrives in a big city and suffers exclusion, citing the example of a boy named ''N.N,'' apparently Norio Nagayama.
     ''I was wondering in those days if students were interested in sociology,'' Mita, 71, said. ''Sociology must show how living people face each other amid distress and agony, and I think 'Tears of Ignorance' provides us with clues to studying issues, such as family, rural as well as urban areas, crime, poverty and discrimination.''
     Mita, now professor emeritus at the university, asked Nagayama in the letter to check whether there were any misunderstandings in his paper. ''I expected a harsh reaction, but he responded he was very interested in my thesis,'' Mita said.
     Kamata, the freelance writer, once met with Nagayama at the Tokyo Detention House, while sending some letters and picture postcards to him mainly from destinations for his research trips.
     A postcard from Sapporo noted, ''They have much more snow here than usual. We used to have much snow in Aomori, didn't we?,'' while another postcard from Naha, Okinawa Prefecture, said, ''You must feel relieved as the spring has come. Please take care of yourself.''
     ''I thought he would be able to feel relaxed when he saw the pictures on the postcards,'' Kamata said. He also encouraged Nagayama to continue writing about his repentance ''as the representative of the golden eggs.''
     Nagayama was said to have regretted that his victims had been just ordinary citizens like he had been before -- two security guards and two taxi drivers. Kamata said the Akihabara killer, who is also from Aomori and lived out of a suitcase, may have the same regrets as Nagayama did.
     ''We will continue to see such people who express their disgust by getting mad, and we have to seriously think about how to face the situations on a societal level,'' Kamata added.
     Nagayama's books include the award-winning ''Kibashi'' (Wooden Bridge) in 1983, and around 15 million yen of royalties have been donated to poor children, particularly in Peru, based on his hope that poor and working children would not slip into evil, as he did, as a result of poverty and ignorance.
     ''We supported Nagayama as he desperately tried to face what he had done, and we wanted him to continue living,'' Michie Ichihara, who keeps the letters, said.
     The Peruvian children who received the donations from Nagayama have said that while they respect his help for them, they will never be a person like him, according to Ichihara, 62.
     ''I'm glad that they understand what Nagayama went through and thought,'' Ichihara said.
     She also keeps carbon copies of some of Nagayama's letters to the senders and hopes the exchanged letters will be used as material to research juvenile crimes so that society will never create another person like him.
     But Ichihara said she also hopes Nagayama ''will be forgotten some day when people do not have to learn lessons from his experiences.''
==Kyodo