Have you heard of K-pop idol cliques? K-pop idols often form groups of friends who like to hang out with each other often and even go drinking together. One of the most famous K-pop idol cliques is the "Kyu-line," which consists of Super Junior's Kyuhyun and Ryeowook, SHINee's Minho, TVXQ's Changmin, and CNBlue's Jonghyun.

How was the K-pop idol clique formed? Well, back in 2011, Kyuhyun shared a hilarious photo on his twitter, showing results of a smart phone application that determines how much normal people's faces resemble celebrities' faces. From the smart phone app, both Changmin and Jonghyun got results that said they looked 100% like Kyuhyun.

Kyuhyun posted the picture along with the caption, "One day I received a photo from TVXQ's Changmin that put me in a state of panic. Additionally, I received a photo from CNBLUE's Jong Hyun that was so shocking I couldn't breathe. This is the Kyu line kekeke"

On an episode of "Radio Star," which is hosted by Kyuhyun, CNBlue's Jonghyun revealed the truth behind the formation of the "Kyu-Line," saying that he was actually forced to join! Jonghyun said, "One day, I suddenly found myself in the 'Kyu-Line.' Kyuhyun hyung said to me, 'Now you are going to be with me,' and I was forcefully recruited."

Jonghyun further said, "When we were practicing for a different program, Kyuhyun hyung suddenly said to me, 'You resemble me a lot.'" Kyuhyun responded to his claims, saying, "I said that because my fans kept saying we look alike!"

Before CNBlue's Jonghyun had the "honor" of joining the Kyu-line, the clique's members have also tried to explain the qualifications of joining the Kyu-line:

Minho: I'm a member of Kyu-line.
Kyuhyun: The members are Ryeowook, DBSK Changmin, and SHINee Minho.
Donghae: I want to join the line as well.
(Kyuhyun and Minho laugh)
Yesung: You should make your own line and call it Donghae-line.
Donghae: No, no, I want to join Kyu-line.
Minho: There are some criteria to be part of the line.
Fans: HEIGHT!
Minho: No, no.
(Yesung points to Ryeowook. They all laugh.)
Minho: No, height isn't one. You must like what Kyuhyun enjoys. The requirements are game and wine. Wine is the most important.

Although the "Kyu-Line" is named after Kyuhyun, Kyuhyun has previously revealed that the actual leader of the clique is TVXQ's Changmin.

Minho once hijacked Kyuhyun's twitter and wrote: "This is Minho ha ha. I'm touched by Kyuhyun's cake. I'm so happy today. Heechul, Kangin, Donghae, Kyuhyun, Changmin, Jonghyun, I love you all~~" The fact that Minho was able to use Kyuhyun's twitter account shows off their close friendship.

SHINee's Jonghyun is also sometimes thought to be a Kyu-line member, but really who makes the cut in the list, only Kyuhyun (or in that case Changmin) can tell. 

The members of the Kyu-Line often meet up for birthday celebrations and also go drinking together, which translates to many drunk birthday moments. Their close friendship is often shown in the photos they take!  

Watch this video as Kyuhyun proudly introduces the members of his "Kyu-Line."

What do you think of the Kyu-Line and its members?