“With help from his Senior Advisor @sykimsy, @USAmbROK Harris visited a classic local barbershop to become a little ‘cooler’ during the hot summer months,” the post reads.
In the video, Harris complains about the recent weather in Seoul before sitting down to get his mustache completely shaved off by barber Mr Oh.
Harris later wrote a post-shave message on his own Twitter account.
Mask-wearing, testing and contact tracing have been important parts of South Korea’s coronavirus response, which has been widely praised.
So far, the country has recorded just over 14,000 cases and 299 deaths, according to figures from Johns Hopkins University.
Harris has been the US ambassador to South Korea since July 2018, and his facial hair previously attracted bizarre criticism from a small section of society.
In January, Harris told reporters his mustache had “for some reason become a point of some fascination here in the media” after he was subjected to heated vitriol online.
The gist of the criticism was that with the mustache, Harris resembled the reviled Japanese leaders who ruled the Korean Peninsula with an iron fist during the Japanese occupation from 1910 to 1945.
Some of Japan’s most prominent wartime leaders — including Emperor Hirohito and Hideki Tojo, the Prime Minister who was later executed by a postwar tribunal– had mustaches.
Under Japanese rule, many Koreans were brutalized, murdered and enslaved. It is within living memory for elderly Koreans and remains a highly emotive subject in both North and South Korea. In recent years, issues relating to Japanese reparations for its behavior in Korea have become a point of contention between Japan and South Korea.
Another issue is that South Korea is a homogenous society where mixed-race families are rare and xenophobia remains common.
Harris was born in Japan to a Japanese mother and American father, who was a Navy officer, and some online commentators have pointed to Harris’ heritage along with the mustache in their criticisms.
But Harris isn’t Japanese, he’s a US citizen. And calling him out for his Japanese ancestry would almost certainly be considered racist in the United States.
“I understand the historical animosity that exists between both of the countries but I’m not the Japanese American ambassador to Korea, I’m the American ambassador to Korea,” said Harris in an interview with Korea Times in December.
“And to take that history and put it on me simply because of an accident of birth I think is a mistake.”
CNN’s Joshua Berlinger contributed to this report.