When Pak Chung Sun met her former boyfriend in Seoul in January, he was no longer the reticent, tender-hearted gentleman with whom she had lived a quarter of a century ago in Tokyo.

Shuffling along, the white-haired Shin Gwan Su, 70, said everything he had done was for the sake of his mother country, North Korea. He raged at her for coming to visit him, shouting that 63-year-old Pak was a "reactionary element."

Shin was released from a South Korean prison in December, thanks to Seoul's "millennium amnesty," after serving 15 years for spying for Pyongyang. It was their first meeting in 17 years.

Before South Korean courts, Shin confessed, among other things, to abducting and smuggling a 43-year-old Japanese man, Tadaaki Hara, into North Korea in 1980 in order to steal the man's identity.

The Japanese government admits that 10 Japanese were probably abducted by North Korean agents between 1977 and 1980, but Hara's case remains the only one that has generated an official confession. The whereabouts of the missing, including Hara, remains unknown.

Japan did not officially acknowledge until 1997 that the 10 disappeared in mysterious circumstances and that they might have been spirited away to North Korea. The revelation came 10 years after a South Korean jetliner was blown up over the Indian Ocean and a woman put on trial for the bombing, a confessed Pyongyang spy who had been traveling on a false Japanese passport, told a South Korean court that she was taught the Japanese language and culture in North Korea by a woman abducted from Japan.

According to the South Korean court, Shin, a Korean national born in 1929 in Shizuoka, went to live in North Korea after the war. He was recruited as an agent for Pyongyang in 1971 and secretly put ashore in Ishikawa Prefecture by the Stalinist state in July 1973.

Pak, also a Japanese-born Korean national, met Shin in October 1973 through a friend of her older brother, An Bok, who had connections with the General Association of Korean Residents in Japan (Chongryun), Japan's biggest pro-Pyongyang organization. At the time, Shin gave his name as Sakamoto.

"(Shin) came to visit me almost every day, asking me to live with him," Pak said during a recent interview. "I first thought he was weird because we had just met each other. But since he offered to pay the rent and look after my children, I finally accepted."

Their life together began in December 1973 in a two-story house in Meguro, Tokyo.

"He was gentle, quiet and methodical. He'd always take care of my children with affection, so they really took to him," Pak said.

Although Shin was a good family man, Pak admits she sometimes felt there was something strange about him.

At night, Shin would tune into coded short-wave radio messages from Pyongyang. He would never go outside before dark, and never wanted anybody to know where he lived. He often bought books about Japan's military.

"At that time, I didn't think he was a spy because he claimed that he worked for the pro-Pyongyang group, and I believed that," she recalls.

In 1976, Shin left on what he said was an overseas business trip. She later received a letter from him from North Korea.

According to the South Korean court, Shin returned to Japan -- again surreptitiously -- in April 1980 on a mission to take a Japanese person between 45 and 50 years old to North Korea.

In June 1980, Shin abducted Hara, a loner and a cook at a Chinese restaurant owned by a Chongryun official in Osaka, and took him to a Miyazaki beach where Shin rendezvoused with four Pyongyang agents. Four days later, they all arrived at a North Korean port, the court said.

When Shin entered Japan for the third time in October 1980, he visited Pak for a week. He no longer went by the name Sakamoto.

"I happened to see his driver's license, which had the name Hara on it, and asked him what it meant," Pak said.

Shin initially explained that he had been naturalized as a Japanese citizen and taken a new surname, but shortly afterward he confessed he was a North Korean spy, Pak said.

Shin was arrested in 1985 as he entered South Korea from Japan with a doctored passport that bore Hara's name and Shin's photo. Another Pyongyang agent under arrest in South Korea had betrayed him to the authorities.

Pak was shocked by the news and by his revelation that he had abducted Hara, but remained silent. Then in 1990, she learned that one of her brothers had been executed in North Korea six months after Shin's arrest in South Korea.

North Korean sources told members of Pak's family that An Bok had been suspected of spying on North Korea.

The suspicion stemmed from a visit he payed to Shin in the late 1970s in an area of North Korea considered an enclave for its agents. The visit was made at the request of Pak, who had learned of Shin's whereabouts from his letter.

Pak believes that her brother's death was due to Shin's failure to report to North Korean authorities that she had helped him in Japan, and that An Bok was her brother.

"I would not have told the whole story if my brother had not been killed," Pak said.

Pak, who has made it clear that the reason she is talking about the time she spent with Shin is her anger over her brother's execution, still harbors affection for Shin.

"Please do something with that nation. Somebody has to change its crazy nature," she told a recent gathering of relatives of Japanese believed to have been abducted by North Korea.

Pak still believes that, in a way, Shin is a victim of the North Korean regime.

"He is a man with a sense of justice. If he discovers something is wrong with the North Korean regime, I am sure he will take action," she said.

Pak plans to visit Shin in Seoul again this summer, this time with her children.

"If (Shin) sees my children, he probably will not shout at me like he did the last time. And he might remember something (about the days we spent together in Tokyo)."