Rubin of the new boy group 1TEAM opened up about the anxiety he felt during his long training period. 

On March 27, 1TEAM held the showcase for their debut album 'HELLO!' at K Art Hall in Seoul. 

Rubin, who has also appeared on 'MIXNINE,' said, "I was under many different agencies. I was part of many groups, and there were times when our debut fell apart. I felt anxious as 1TEAM's debut date got confirmed and approached."

Rubin shared his current agency, Liveworks Company, regularly provides different lectures. One of the lectures for trainees is stress management. 

Rubin said, "The lecturer said, 'Humans don't need to be perfect. It's okay to take a break on the way.' At the time, I had anxiety in me, so I got teary and also felt encouraged. I tried not to be so hard on myself."

He added, "Today is the showcase that I've been dreaming of. I couldn't sleep for several days... There were many people who've waited for this. I will become a harder working Rubin of 1TEAM."