SHINee revealed the secret to their long-running success during the showcase for their new album '1 of 1'.

The group of 9 years shared they had unbreakable bond. Jonghyun first explained, "We've seen each other for 10 years since our trainee days. The thing that I consider the most important is not to listen or talk about each other's private lives. That's most professional."

SEE ALSO: SHINee shares group photo for SM Entertainment's 30th anniversary without Taemin, sparking mixed reactions

Minho added, "We know what each other like and hate. Also, if there's a member who is struggling, then the member with power helps him up." Key also chimed in and said, "I don't think we are conscious about teamwork. That's how we make it naturally flow."

It sounds like SHINee's considerate thoughts and understanding played a huge role in their successful teamwork.