Protesters hold light sticks for K-pop group NCT during a rally, demanding President Yoon Suk Yeol's impeachment in Yeouido, Seoul, Saturday. Screenshot from X

K-pop light sticks of all colors glowed during the massive rally in front of the National Assembly in Seoul on Saturday, as protesters voiced support for the impeachment of President Yoon Suk Yeol.

Young women protesters in their 20s and 30s, rooting for different K-pop groups, including SHINee, NCT, NewJeans and Seventeen, joined the protest holding their light sticks, singing along and chanting slogans.

A light stick refers to official fan merchandise priced between $30 and 50, offered by each K-pop group for events such as concerts. Fans use them to cheer for their idols.

As the plenary session of the National Assembly began at around 5 p.m., the protest transformed into something akin to a K-pop music festival. Participants danced and chanted together to K-pop hits such as aespa's "Whiplash," Rose's "APT." and Seventeen subunit BooSeokSoon's "Fighting," modifying lyrics to criticize Yoon and demand his impeachment.

The trend developed over the week during daily candlelight vigils held in front of the National Assembly, following the sudden declaration of martial law on Tuesday night.

"Dear K-pop fans across the country, please bring your light stick to the rally. We will hold a candlelight concert for you," announced Candlelight Action (@candlemove), a civic group organizing the rally, said Thursday on its social media.

"At the time of Park Geun-hye's impeachment, some lawmakers said, 'The candlelight will go out when the wind blows.' That's why I brought this light stick because there is no way anyone can turn this off," Cho, a 24-year old NCT fan who customized her light stick to bear the word "impeachment," said.

Many others who were unfamiliar with fan culture found it fascinating and enjoyed the new, festive aspect of the country's protest culture.

A participant holds a K-pop group light stick during a rally in Yeouido, Seoul, Saturday. Korea Times photo by Park Si-mon

"I realized that the protest culture has changed a lot. It's more fun and joyous," Kim, 52, who had participated in the candlelight rallies seven years ago for the impeachment of former President Park Geun-hye, said.

Lee, 59, said he will make sure to bring something as bright as the K-pop light stick next Saturday. "I expected more people from my generation to come to this rally, but surprisingly, there were so many young women. I was so moved and touched to see the colorful glow and bright energy made by them," he said.

K-pop fans said they developed the know-how, persistence and love from their fan activities, citing that their skills turned out to be useful for the protests.

"We (K-pop fans) are very used to waiting outside in the cold. We are also good at shouting and cheering aloud for what we love. I see that in protest it is no different," a Seventeen fan, Heo, 24, said.

She added, "Our protest will be fun and cool, just like a concert. That's why we will come back tomorrow and invite more people to join us. Come and see."

Protesters hold light sticks for K-pop groups during a rally in front of the National Assembly in Seoul, Saturday, urging lawmakers to vote for the impeachment of President Yoon Suk Yeol over his short-lived martial law. Yonhap