SEOUL, South Korea — Divorced and out of money, Kwon Chol-nam fled North Korea for China in 2014 by wading across a river border at night and then crawling over a barbed-wire fence. After a perilous trek that included walking through a jungle in Laos, he reached Thailand, where he was allowed to fly to South Korea to start a new life.

After all that trouble and danger, Mr. Kwon now wants South Korea to allow him to return home to the North.

“You have to ride a horse to know whether it’s the right mount for you,” Mr. Kwon said in an interview in Seoul. “I have tried, and the South is not for me. I want to go home to the North to reunite with my ex-wife and 16-year-old son.”

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North Korea is one of the world’s most politically repressive countries. No matter. Mr. Kwon says he has grown disillusioned with life in the capitalist South, where he says North Korean defectors like him are treated like second-class citizens.

“They called me names, treating me like an idiot, and didn’t pay me as much as others doing the same work, just because I was from the North,” Mr. Kwon said, his voice rising in anger.

To press his unusual demand, he has held news conferences, submitted petitions to the United Nations and demonstrated with signs in front of government buildings in Seoul.

More than 30,000 North Koreans have fled to South Korea since a famine hit their homeland in the 1990s. Of them, 25 have mysteriously resurfaced back in the North in the past five years.

South Korean officials suspect these “repeat defectors,” as those who return to the North are known, may have been lured to China and kidnapped back to the North. There, the government uses them for propaganda, arranging for them to speak out against the “living hell” they said they had experienced in the South.

Mr. Kwon tried to find his own way back to the North, but that effort only landed him in jail in the South for a few months. Like all defectors, he became a South Korean citizen upon arriving here, and it is illegal for any South Korean to visit the North without government permission.

Now, he is openly asking the South to repatriate him, only the second defector to make such an appeal. Kim Ryen-hi, a dressmaker from the North, has been on a similar campaign since 2015.

But on the divided Korean Peninsula, where the two countries remain technically at war and don’t even let their citizens exchange letters, going home across the sealed border is a near impossibility.

For defectors like Mr. Kwon who have failed to adjust to life in the South and want to return to the North, there is no legal way to do so.

“These cases highlight the complexity of the family separation issue that started 70 years ago — and the fact that it continues to take new forms and affect people in the Korean Peninsula in profound ways,” said Tomás Ojea Quintana, the United Nations’ special rapporteur on human rights in North Korea, who met Mr. Kwon in July.

Mr. Kwon’s case has provided a propaganda boon to the North. “As we can learn from the tearful outcry from Kwon Chol-nam, who said he could no longer live in a hell called South Korea, there are many of our citizens forcibly held in the South and yearning to return home to the fatherland,” the North said in a statement in June. It added that his situation showed the South’s talk of humanitarianism was “a hypocrisy.”

Mr. Kwon, 44, was working as an herb dealer near the border with China in 2014 when he and a woman he had met while collecting blueberries fled across the border. The woman had been in China before, and she told Mr. Kwon that he could make money in China, a lot of it.

But once he made it there after a harrowing border crossing, nothing went as expected.

The woman disappeared. Mr. Kwon ended up with a human trafficker who promised to get him to South Korea, for about $2,500. After an arduous journey that lasted a month, he arrived in the South in November 2014, settling in Ulsan, an industrial city in the southeast.

But like other defectors, he struggled to make the transition from the North’s highly regimented totalitarian system to the South’s fast-paced, hypercompetitive capitalist society. (About 63 percent of defectors say they experience discrimination in the South, according to a study by the government-run Korea Institute for National Unification last year.)

Mr. Kwon drifted from farm to construction work. He was often ridiculed for not understanding the English words South Koreans liberally adopt in their daily conversation. Just over 5 feet tall, Mr. Kwon didn’t see a future in physically demanding jobs.

The more he struggled, the more he missed his family in the North, especially his son. He saved $4,500 and, using intermediaries because no banking transfers are allowed between North and South, sent it to his ex-wife in the North, who told him that she wanted to be reunited. He also felt guilty for leaving home after he learned that his father had died while he was away. To add to his woes, the broker who smuggled him from China to Thailand sued him, accusing him of not paying all of his fee.

Then in May last year, Mr. Kwon said, he finally “snapped.” When he didn’t get the pay he said he had been promised for carrying bricks, he asked the police to intervene, but they sided with his South Korean boss, who denied Mr. Kwon’s accusation.

“I will go back to the North and hold a news conference there to tell the truth about what the life was like in the South,” he yelled at them, according to court records.

His escape from the North first made him an enemy of Pyongyang, and now his desire to go back has made him a pariah to some in the South.

Homesick, Mr. Kwon watched North Korean propaganda on the internet. He applied for a South Korean passport and a tourist visa to China so he could enter North Korea from there. He converted his savings to dollars. He even sent goodbye text messages to a police detective he had befriended, saying he was moving “abroad.”

“I no longer want to live here heartbroken,” he texted.

On June 22 last year, a dozen police officers raided his home and arrested him on a charge of plotting to flee to North Korea, a crime punishable by up to seven years in prison. Mr. Kwon was released in September after a judge suspended his one-year prison term.

He has since been out of work, and his fellow defectors shun him. He was reduced to smoking dirty cigarette butts off the ground.

“I went through difficulties in the South that I hadn’t known in the North,” he said. “I am afraid to live in the South.”

Mr. Kwon moved to Seoul in March and stayed in homeless shelters before renting a room for $267 a month. He found help in sympathetic Christian pastors.

“It’s a most natural thing for a human to want to go home to his family,” the Rev. Moon Dae-gol said. “A state that denies that right is no better than a beast.”

During his protests in front of government buildings, Mr. Kwon holds a sign that says: “I am a citizen of the Democratic People’s Republic of Korea. I want to go home.” Some accuse him of being foolhardy. But he remains undeterred.

He said he was not afraid of being punished in the North for fleeing, although he added that he expected to be sent for re-education for a period and that this was a price he was prepared to pay. He said he was proud of the North’s nuclear weapons. He would not accept any criticism of North Korea, and its human rights abuses, and vowed to “stay loyal to the end.”

It was difficult to tell whether Mr. Kwon was being sincere or just trying to endear himself to the North.

But his conviction was clear when he emphasized that while South Korea was economically better off, he preferred a simpler life in his birth country.

“In the North, I may not be rich, but I would better understand people around me and wouldn’t be treated like dirt as I have been in the South,” he said.