Travel YouTuber Kwak Joon-bin, better known as KwakTube, touched a nerve with the public concerning bullying when he posted his latest video featuring Lee Na-eun, a singer-turned-actress who was accused of bullying her former bandmate in the now-disbanded K-pop group April.

Kwak on Monday posted a video of his travels in Italy during which he met Lee. He told Lee about how he misunderstood her because of now-disproven allegations of school violence. Police launched an investigation into the allegations in 2020, leading to the accuser admitting to lying about and apologizing to Lee.

"I'd blocked you (on social media) off because I was sensitive toward school bullying, but I unblocked you after I saw the news. I felt like I was imposing secondary damage to you because of misunderstanding," Kwak said, to which Lee replied that such misunderstanding made her sad.

But what stirred the controversy was another allegation surrounding Lee. In 2021, she was accused of bullying groupmate Lee Hyun-joo when they were both members of April. The related police investigation in 2022 found evidence of discord among members, but the incident was never legally defined as bullying.

Neither Kwak nor Lee addressed the bandmate bullying allegation and talked only about the school bullying.

The incident caused more public discontent as the 32-year-old YouTuber has been one of the most outspoken critics of bullying here, having frequently spoken about the intense bullying he experienced for most of his school years due to his looks and socio-economic status.

Lee's history of dropping out of high school early and pursuing higher education before becoming a government official and celebrity was considered inspirational to many fans. Kwak's backstory and relatability culminated in over 2 million YouTube subscribers and him becoming one of Korea's most beloved internet celebrities.

But his recent video was bombarded with comments expressing disappointment toward him about supposedly being insensitive to the issue of bullying, despite being a bullying victim himself.

Unlike Lee's school bullying accusation, the dispute surrounding her former April groupmate was not so black-and-white. Police dropped the case without pressing charges while acknowledging that "a general problem in the interpersonal relationship occurred within a group, but it cannot be definitively said its nature was bullying."

Kwak deleted the video hours later and issued an official apology.

"There were parts in the video I did not think through about. I will be careful not to speak for everyone else with my personal beliefs," he said, reiterating that he was sorry for causing discomfort for viewers.

It is unclear exactly what happened between members of April, with conflicting testimonies from both sides, but several of Kwak's fans are expressing disappointment at what they feel are insensitive actions on his part. They said Kwak had no right to depict Lee as a good person when she was accused of bullying other people.

"Lee Na-eun would have been a good person to Joon-bin. He would've thought 'Huh? She's a good person. This is all a misunderstanding. Go talk to the people who are friends with those who bullied him. I bet they'll tell you the same thing," one of the users commented on the official apology posted on the KwakTube channel.

"Joon-bin has been blaming the perpetrators of his bullying, said the experience left him traumatized, yet he is 'forgiving' (Lee) because she was a good person to him."

As of Wednesday, Lee has not issued a statement concerning the matter.

Whether or not Lee Na-eun bullied Lee Hyun-joo has not officially been proven, but the incident and the ensuing controversy over the YouTube video are already having an impact.

The Ministry of Education, which posted a promotional video for its anti-school bullying campaign starring Kwak last week, hid the video from public view on its official YouTube page after the controversy.

A petition calling for Kwak to be removed from the panel list for the upcoming International Travel Fair in Busan was posted on the state-run e-People website, alleging that it is inappropriate for him to address the public while embroiled in such controversy.

Some even heckled the celebrities related to Kwak or Lee, such as one who sent an Instagram message to Pani Bottle -- a fellow travel YouTuber who is a close friend of Kwak. The person accused him of posting an Instagram story despite his friend having fallen from grace and said he should take the fall with Kwak, to which Pani Bottle responded with profanity.