Actor Lee Jung-hyun shared that he was once criticized after singing the Korean national anthem during a ceremony for Liberation Day, as some people confused him with being Japanese because he keeps being cast as playing Japanese characters in dramas and movies.

During JTBC's Knowing Bros (Liberation Day special) on Aug. 16, Lee was featured with Choi Tae-sung and Jang Ye-won.

"I was able to participate thanks to my ancestors. My maternal grandfather was a national merit honoree," Lee said.

In response, cast member Lee Soo-geun joked, "Those who called someone like him 'Japanese' are in big trouble now." Lee explained.

To this, cast member Lee Soo-geun made light of, saying, "I received a lot of complaints asking why a Japanese person was singing the Korean national anthem. Since it was right after Mr. Sunshine, the misunderstanding was even greater."

Lee revealed that his grandfather, a veteran of the Korean War, received a posthumous Order of Military Merit Hwarang Medal in 2020.

READ MORE:'Out of Touch?' Lee Jung-hyun's Lavish Kitchen Tour Sparks Backlash Amid Economic Woes

"He had many metal fragments inside his body. When preparing to place him in the National Cemetery, he had to be cremated, and so many traces came out," Lee added.

His experience made Kim Hee-chul bow in apology, and Seo Jang-hoon commented, "When you appeared in Mr. Sunshine, I thought they actually cast a real Japanese person. This should be widely known because many people still misunderstand you as Japanese.""

Lee then reminisced about singing the national anthem at the 73rd Liberation Day commemoration. "As a descendant of a national merit honoree, I was invited. I thought my grandmother would watch proudly, so I sang it loudly," he said. But Lee Soo-geun added jokingly, "Doing that during a choir is considered bad manners."

The performance attracted unforeseen criticism, according to Lee. "I got many complaints about why a Japanese was singing the Korean national anthem. Because it was just after Mr. Sunshine, people's misunderstanding was even more.

Renowned for playing Japanese antagonists, Lee said, "The ones that left the strongest impression were Anarchist from Colony, Three Kingdom Wars – Imjin War 1592, and Mr. Sunshine. I think I spoke plenty of Japanese in those roles."

Lee, who went to study abroad in Japan, explained he spent one year on exchange to master judo."I couldn't speak Japanese natively. Luckily, I had lots of Zainichi Korean acting friends such as Oh Sang-yoon and Han Geon-tae who supported me a lot during productions."

When asked whether author Kim Eun-sook asked him to speak in Japanese during his audition for Mr. Sunshine, Lee explained, "Actually, I didn't audition because I was cast due to Anarchist from Colony. I think that's why I did well."

He continued that he delved deeply into the characters. "I practiced a lot — even little gestures like sticking out my tongue. Some of those habits still remain.."

On issues of being stereotyped as villains, Lee confessed, "I worry a lot, but sometimes I do get cast in romance roles too. Honestly, I think playing villains gave me more opportunities. For example, I also appeared in The Nice Guy — though I was a bad person there too," he exclaimed laughing.

READ MORE: Lee Jung Hyun's Mother Dies at the Age of 73