On the November 5 episode of the YouTube channel CBS Renew, missionary Lee Seong-geun best known as the father of AKMU opened up about his daughter Lee Su-hyun’s emotional slump and the sibling duo’s evolving relationship.

Titled “The Roots of AKMU: A Father’s Life and Faith,” the video featured Lee sharing behind-the-scenes stories about AKMU’s rise to fame and the personal battles they’ve faced along the way. He recalled when his children participated in SBS’s K-pop Star 2, where they ultimately won: “The kids said they wanted to try it. I thought they wouldn’t last long, maybe get eliminated in the early rounds. I had to return to Mongolia, so I told them I’d go ahead and they could join me after they were done. But six or seven months later, they ended up winning.”

Lee Su-hyun and her brother Chanhyuk were homeschooled in Mongolia and were each other’s only friends during their upbringing. However, Chanhyuk’s military enlistment triggered a long period of emotional struggle for Su-hyun.

“We didn’t realize what was happening at first,” Lee said. “Through a broadcast, we later learned that Su-hyun had always enjoyed singing while Chanhyuk took the lead. But when he enlisted, she was forced to take full responsibility. That fear and pressure started her slump. She told us, ‘Now I understand what kind of weight my brother carried alone.’”

According to their father, Su-hyun’s emotional burnout began around the time of Chanhyuk’s enlistment. “She tried to fill in his absence by working harder, but it completely drained her energy. Neither we nor she recognized it at the time,” he explained. “Since March, the two have been living together again, and the whole family is focusing on supporting her.”

Lee Su-hyun slump AKMU

Chanhyuk also responded in his own way. He wrote the song “Love Lee” for Su-hyun, a track that marked a turning point. “It seems Chanhyuk had a revelation during his military service,” their father noted. “He realized he had to do what he truly wanted with his life. So his songs and activities afterward reflected his own tastes and goals. But that shift made things harder for Su-hyun. She said she found it difficult to sing his songs they didn’t match her style, and it became a burden. She eventually lost the joy of singing.”

Lee continued, “After Chanhyuk explored his personal ambitions through his solo album, he finally turned his attention to Su-hyun. Although she’s still an active celebrity with offers pouring in, she had lost motivation. In the past, Su-hyun would say, ‘I still want to sing songs like Give Love and 200%,’ but Chanhyuk had refused, saying he couldn’t write songs like that anymore. Then he decided to give it a try and Love Lee was born. That song brought Su-hyun back to the spotlight and reminded her why she loves music.”

Sources: nate