They may now be one of K-pop's most dynamic duos, but there was a time when TVXQ singer Max Changmin claims he was terrified of his bandmate U-Know Yunho.

In an interview Tuesday on the South Korean cable talk show "Beatles Code 3D," Changmin recalled his initial fear of his future collaborator, which happened when they both were being groomed for stardom by their record label SM Entertainment.

"Not that he gave me a hard time, but I could tell that he was being territorial when I first joined SM," he said, according to eNEWS. "Yunho was scary and strict towards the new trainees."

Yunho brushed off Changmin's tales of his bullying as relating to the intensity he felt at the time for the record label's badminton team.

"[When Max Changmin first arrived at SM] was the time when teams were being formed for the team and many trainees would quit and leave," he explained.

"Then Max Changmin, who played badminton before, joined the team all of a sudden. So I told him 'If you came here to play around, just quit now.'"

Changmin admitted he was baffled by Yunho's attitude at the time.

"I thought he was strict to everyone younger than him, but he was really nice to Urban Zakapa's Kwon Sun Il and he was the same age as me," he said.

"So I wondered, 'why is he only nice to him when we're both younger than he is?' I tried to avoid Yunho back then."

The friction between the duo reemerged when TVXQ band members Hero Jaejoong, Micky Yoochun, and Xiah Junsu left the group in 2010 over contract disputes with SM Entertainment and started the band JYJ, turning the five-piece into a duo, which it would remain.

"It felt different to interact with Yunho one-on-one, versus in a group situation," Changmin said.

"We had to accept and understand everything about each other. I couldn't understand why I had to be responsible for so many things. We fought a lot, four years ago."

Yunho agreed.

"We did fight a lot in the beginning, but in the end, it only made us closer friends," he said. "I've always thought I was the one better than him, but people have been telling me recently that he's more talented than I am."