Every morning at Sungwon Daycare Center in Seongsu-dong, Seoul, when children exchange their hellos, the routine is to go around asking each other how they feel.
"I am sad," says one of the five-year-olds in the classroom. "Why?" the whole class asks him.
"Because my mom came home late last night. I couldn't see her before going to bed. And when I woke up this morning, she already left for work."
"It's OK! It's OK!" the kids tell him loudly with impish grins, as the teacher consoles him. "Going to work doesn't mean your mom doesn't love you. I'm sure she misses you at work right now."
At Sungwon, one of the state-run day care centres, children arrive as early as 7.30am and stay as late as 9pm. Many of them are children of double-income families, whose parents don't have any extended family members to help with child care.
As of 2013, there are more than five million double-income households in Korea, accounting for 43 per cent of all households in the country.
With an increasing number of women in the workforce, along with poor work-life balance, more young parents are said to be suffering from parental stress, which inevitably reflects on the well-being of their children.
Park Chun-hwa, one of the day care workers at Sungwon, said she's been witnessing a growing number of children with behavioural and developmental problems ― many of them apparently resulting from the lack of interaction with their parents.
One of the kids she's taken care of, who was 3 years old, hadn't been toilet trained and arrived at the centre wearing diapers on his first day.
"I would train him during weekdays, but he'd return the next week in wet diapers again," she told The Korea Herald. "Being busy as a working parent is one thing. But there are also responsibilities that all parents should be fulfilling."
For a 30-year-old working mother surnamed Jung with a four-year-old son, the biggest challenge about child care is the sense of helplessness. With both her parents and in-laws living about four hours away from Seoul, Jung currently sends her child to a day care centre, where he spends about eight to 10 hours a day.
"On top of the stress from work, the worst feeling is this sense of living in the dark," she told The Korea Herald.
"I'm supposed to be in charge of child care but very often I have no idea if I'm doing it right. My son was a late talker, and I was devastated thinking it was my fault (because I couldn't quit my job for him). I would constantly think I may be doing something wrong and it would make me anxious, guilty and even depressed."
Overseas studies have long shown that personal stress influences a parent's behaviour toward their children.
Parents who are financially struggling or having marriage stress have a higher chance of abusing ― or neglecting ― their children, according to a 1991 study by Michigan State University.