The coronavirus crisis means millions of parents around the world are grappling with the challenge of home-schooling. But one man in Seoul has a particularly tough task.
Kim Tae-hoon, 45, homes 10 North Korean boys who defected from the repressive state without their parents. The youngest is just 10 years old, the oldest 22.
Usually they would be at school, or university - in the case of 22-year-old Gun-seong - but last month South Korean students began online lessons instead.
On the first morning of remote schooling, Kim, talking to the BBC via video link, shepherds the boys to a large table on the second floor, where the wifi is at its strongest.
"I think you'd better put your earphones on because the sounds might get all mixed up during the morning assembly," he tells them.
As might be expected, there are teething problems. Grappling with unfamiliar online systems via tech devices rented from the local education office is one of them.
The log-ins of two of the boys who are in the same grade have been mixed up, and 15-year-old Geum-seong, who only defected from North Korean a year ago, understandably needs more help than the others. He's not used to submitting assignments online.
Meanwhile, Jun-seong, the youngest of the family, is scolded for watching YouTube on his tablet.
But just two days later, Kim says the boys have settled into their new routine under his watchful eye.
Eight of Kim's charges defected without adults, either alone or with siblings, and have no other family ties in the South. There are various reasons for just children leaving North Korea, including living only with grandparents too elderly to accompany them, or having parents who live apart and cannot organise for the whole family to make the difficult journey.
"They send their child to South Korea to find a better life. If the kids are too young, they even escape from the North on the broker's back," Kim explains.
According to the Ministry of Unification, there were 33,658 North Korean defectors in the South as of March 2020, of which around 15% were 19 years or under.
And as of 2017, the government reported it was aware of 96 children who had arrived in the South without their parents, according to media reports.
Kim never imagined that he would become the boys' carer.
Fifteen years ago he was working in publishing. He spent his spare time volunteering for Hanawon, a government-run resettlement facility in Seoul where all North Korean defectors live for three months, taking a course to prepare them for integration into society in the South.
He met a young boy called Ha-ryong, who had recently left the centre with his mother. She had managed to get a job but it was a long way from home and she had to leave her son home alone.
Ha-ryong, 10 years old at the time, asked Kim to be his babysitter, a role which he ended up taking on permanently.
Kim's parents completely disapproved and cut all ties with him for several years.
He went on to take in more North Korean children, one by one. The boy who has lived with him the longest of those still with him is Cheol-gwang. He arrived in the South on Christmas Eve 2012 aged just 11 years old. He and his sister had initially tried to escape with their mother but were caught by guards and detained. He was released alone, and his sister was freed three months later. But his mum never reappeared.
Eventually Cheol-gwang and his sister succeeded in escaping to the South alone.
As his family grew, Kim registered with the South Korean Ministry of Health and Welfare to form what is known as a "Group Home" - the smallest form of institution in the country which can offer children without parents or guardians an alternative family setting.
"But my kids think of it as a real home, not a facility," Kim says. And his parents have finally accepted his decision and are now his most ardent supporters, treating the boys as their adoptive grandsons.
Geum-seong admits that he was afraid of Kim at first.
"When I first saw him, I thought he was a bad guy. Because a man with a big belly in North Korea is usually a high-ranking official," he says shyly, his accent still very evidently North Korean.
Kim says the logistics are challenging, but he does all the chores himself.
"The hardest part is grocery shopping. As they are growing boys, they eat like horses. I load up my cart with huge amounts of food, but it's frustrating because it'll all be gone in just a day," he says.
The food is unpacked into six fridges. Two washing machines run non-stop every day. Kim needs to vacuum the house constantly.
But he says he doesn't ask the boys for help, arguing that the most important thing is that they are nurtured.
"I don't ask them for anything other than to grow up with decent manners… That's how I was raised by my parents."
It is so much work that Kim is unable to hold down a regular job, but he is eligible for some government benefits and corporate aid.
He says he doesn't feel comfortable taking financial help, however, and so recently he has opened a small cafe in an attempt to gain some economic independence.
But it is not just financial challenges that Kim and his foster family have to overcome.
There is considerable prejudice against North Korean defectors in the South.
Kim initially had to move house fairly regularly as a result of rising rent or the need for extra space as he took in more boys. He says whenever he did so there would be unwelcome attention.
"Whenever we moved, neighbours would somehow find out… Some even sent me a message to warn me that defectors should live discreetly."
On one occasion Kim's household was even visited by police. A fellow pupil of one of Kim's foster children had claimed his classmate was a spy for North Korea.
This was an extreme case, but nevertheless the boys are sometimes taunted, usually when they first join a new school, called names such as "war-causing bastard."
"When South Koreans hear that someone is from North Korea, they tend to look down on them, and some even show hostility. It's so sad because my kids are still teenagers. They shouldn't be viewed politically," Kim says.
In fact many young North Korean defectors drop out of mainstream schools as a result.
"I'm not saying alternative schools are bad. We just don't need it because I can fully support my children from home. I believe having [South Korean] friends and creating memories at regular schools will be a big asset to these children," he says.
Seven years ago, one of the boys, Jin-beom, decided to run for student president.
His teacher rang Kim to say he was worried the experience would prove traumatic for the boy. Kim said Jin-beom would be even more hurt if he knew his teacher had made the call. Despite this, he was voted in by the students.
Every year the family chooses a project to do together. Sometimes it is an art exhibition, sometimes a musical. Most recently it was a travel book showcasing photos the boys had taken of South Korean scenery.
"My boys said that they were curious about two things when they were in Hanawon before entering Korean society," says Kim.
"One was what [South] Korea looks like... and the other was what if South Koreans don't like me?" he said. "So we decided to document Korean scenery while travelling around."
The idea is to donate copies of the book to children in Hanawon to help them lose their fear of the unknown.
As for Kim's charges, they are excited about their futures in South Korea. Their ambitions currently include comic book writing, architecture and athletics. Ha-ryong, the little boy he first took in, has already left, and is in his final year of university where he is studying sociology.
But whatever happens in the future, Kim says his doors will always be open.
"We will still be a family," he says.
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