Former South Korean air steward Park Chang-jin never imagined a bag of macadamia nuts would lead him to a career in politics.
Park -- now seeking the chair of South Korea's third-largest party -- was on the receiving end of what became known as the "nut rage" incident six years ago, when he was made to beg on his knees by a South Korean airline heiress.
The episode made headlines worldwide and turned him into a symbol of workplace abuse in a hierarchical society.
In December 2014, a Korean Air flight from New York to Seoul had a particularly demanding passenger in first class: Cho Hyun-ah, the daughter of the chairman of the South Korean conglomerate that controls the flag-carrier, and a senior airline executive herself.
When a stewardess presented her with a bag of pre-departure nuts, Cho flew into a rage, screaming they should have been served on a plate.
"A flight attendant came to me... looking half-dead, telling me Cho had gone mad with her over the nuts," said Park, who was then the cabin crew chief.
Cho ordered them both to kneel in apology and berated them.
"I implored her to calm down," Park said. "But I could feel my dignity as a human was falling apart... It was the longest five minutes of my life."
Cho pushed him away and demanded he left the plane, then ordered the taxiing aircraft back to the gate -- actions that later saw her convicted of violating aviation safety laws.
"Walking back into the terminal felt like walking into my coffin," said Park.
- 'True nature' -
The encounter with Cho, he said, had given him "a new perspective on society and the true nature of human beings".
"I realised that without a change in politics and laws, the status quo would never change."
After the incident Park -- who at 49 retains the clean-cut looks and polite manner of his former role -- was demoted to the same rank he held when he first joined the company.
A court later ordered Cho and the airline to pay him 100 million won ($90,000) in compensation, and he left the firm in January to go into politics full-time.
He is now seeking the chair of the left-wing Justice party in a vote to be announced this weekend.
- 'Top-down management' -
South Korea is dominated by a few sprawling conglomerates known as "chaebol", whose founding families often retain only small ownership stakes but maintain control through complex webs of cross-shareholdings, with family members rapidly promoted up the hierarchy.
Workplace bullying is more common at firms managed by the controlling family rather than unrelated professionals, according to Chung Sun-sup, head of corporate analysis firm chaebul.com.
"One of the reasons is non-family professionals are more likely to understand and empathise with subordinates because they were once in that position themselves."
Park believes that chaebol family successions "should be stopped in principle".
"But since that can't happen overnight, we need a system that holds them accountable for their actions," he added.
"Everyone should be equal before the law."