About 50 North Koreans under the age of 24 enter South Korea every year without family, according to the South's government. These children only make up about 2% of all North Korean defectors who enter the South.
Some North Korean orphans who survive the treacherous escape from their homeland by way of China end up in South Korean boarding schools, dormitories or group homes.
Adoption in South Korea is not a common practice, but Gwak said "adopting is natural, and worthy."
"There are some South Koreans who adopt our school's children, although not many," he said. "Children here with South Korean adults who don't officially adopt, but act like their parents make unbelievable progress."
We recently traveled to Seoul to meet some of these orphans and the people caring for them. Originally we wanted to learn more about their lives in South Korea -- what it's like trying to integrate into an alien society after living in one of the most isolated countries in the world.
We visited Gwak's school earlier this year -- on a majestic campus more fitting for a temple, tucked away in snow-crusted hills about an hour from Seoul. We also visited the Seoul home of a pastor who is raising five North Korean orphans.
In both places, we met children and teenagers scarred by their experiences. Although we could not independently confirm the details of their individual histories, advocates who work with them say they have heard consistently similar testimonies.
We also heard stories of children struggling with South Korean culture, targeted by bullies, befuddled by K-pop and puzzled by mundane tasks like managing money and taking public transportation.
But we also got a glimpse into the underbelly of the Democratic People's Republic of Korea -- from the perspective of those who occupied one of the lowest rungs of society, far removed from the idyllic vision portrayed in the nation's propaganda.
'I am going to die'
Not long after running into her mother in the streets, Yoon Hee fell ill. Alone and 10 years old, she lay in the snow as the icy winter descended in North Korea.
Eventually, Yoon Hee caught what she suspects was typhoid, leaving her in a hell of fire and ice. Although she lay in the snow about two weeks, no one offered help or food.
She tried to muster her energy to sit and wiggle her fingers and toes, but her hands and feet barely budged -- they were frozen in place. She could no longer move.
Surely, this was it, Yoon Hee thought. She prepared herself. "I am going to die."
Yoon Hee would become yet another corpse rotting in the street -- she had seen the frozen corpses on the roadside because no one bothered to bury bodies of strangers.
A voice interrupted her feverish daze.
A villager had appeared. Yoon Hee recognized her as a woman who was struggling to feed her own children.
The villager thrust money into Yoon Hee's hand. Her voice was firm: "You have to survive."
Helping defectors escape
In North Korea, homeless children like Yoon Hee are called "kotjebes," or flowering swallows. Like the bird, these children are free to roam, unconstrained by the country's societal norms.
Without parents, family or schooling, they don't have as much exposure to the state propaganda that is engrained from childhood, according to advocates. When they escape to neighboring China, it is not so much for political reasons, but to find food.
A U.N. assessment in March found that of the country's estimated 28 million people, 16 million are chronically deprived of food.
Peter Jung is among those working on behalf of North Korea's orphans. Based in Seoul, he leads Justice for North Korea, which describes itself as a "volunteer, non-partisan, grassroots organization" that opposes human rights violations in North Korea.
Jung first met North Korean orphans in 1998 in northern China, where he had gone to learn Mandarin.
Jung was stunned to see the stunted size and condition of North Korean orphans. "It was too shocking to believe," Jung said. "There were children who had skin diseases and with bloated stomachs, collapsing in the streets because of malnutrition."