Famous Taiwanese actor Kai Ko (Ko Chen Tung) attended IU's concert in Taiwan and received criticism for not cheering enthusiastically, and subsequently apologized.

On April 7, Taiwanese media ETtoday reported that Kai Ko's behavior during IU's 'H.E.R' world tour concert held at Taipei Arena the previous day had been captured on camera and was receiving criticism. The report mentioned that Kai Ko was present at IU's concert, where he was observed to as being not enthusiastic, even though he had front-row seats.

Before the concert started, he expressed his excitement on social media, saying, "I'm excited because of IU," revealing his anticipation for the concert. However, there was a witness account about Kai Ko after the concert, and a netizen claimed, "Despite sitting in the front row, he didn't cheer enthusiastically."

As criticism grew, Kai Ko eventually apologized. He posted on social media, "I didn't know I needed to practice cheering to meet my dream idol. I'm sorry," and bowed his head, promising to "practice" IU's cheer.

Kai Ko is known as a fan of IU. He also expressed that the concert had given him a lot of inspiration and enlightenment. He said, "The 6,600 Taiwanese dollars (approximately 206.11 USD) spent was worth it. I could pay ten times more," expressing that he still enjoyed the concert despite the criticism.

On another note, Kai Ko gained much love for his role as Cheng Zheng in the 2011 movie 'You Are the Apple of My Eye'. He also gained popularity in Korea and received much love.