Group Name: A-Peace (Previously: Double B 21)
Company: Golden Goose Entertainment
Number of Members: 21
This group technically debuted in late 2010, but that was only one of the sub groups (sub group issue will be explained later), so they’re still a 2011 group. This group might be a bit confusing because they’re supposed to have 21 members, which alone is sure to be confusing, but their ‘debut’ music video only had seven members in it. This is because they’re split up into four sub groups. 
Last October they released a music video for their song SOS. The music video isn’t what you’d think of when you think music video. It’s footage of a photo shoot; the good part is that we glimpse all 21 members. 
The video on linked article was deleted, so here’s a different one.
I like the song, but my head is spinning because there are SO MANY MEMBERS! I’m someone who is bad with names, it took me quite a while to learn all 13 Super Junior member’s names and match them with faces. I hurts my brain to even think about learning 21 members. However, like I said they’ll be debuting in sub groups of seven members, and learning them seven at a time should make it easier.
Most places say there are three sub groups, but I’ve found names for four. They are: Sky (which debuted August 25), Earth, River, and Burning. The sub group Sky is comprised of the seven members:  I’ve included addition information about the members I’ve found. 
Blood Type: O
Height: 185 cm
Hobbies: Basketball, singing, dancing.
Additional Info: Former member of Xing
Sky came out with a music video called One.
They did a live stage for One on August 25, 2010
“Here are the members: 0:53 – Im Hojung 1:01 – Hyeongseong 1:15 – Kim Wancheol 1:32 – Min Jinhong 2:29 – Kim Seunghyeong (on the right) 3:04 – Jeong Mansoo 3:20 – Haneul” Youtube User: sujuaddict0115
During their debut stage they also performed “Stand By Me”, and I have to say, their English is pretty good.
I discovered a short clip from a variety show, which I believe to be MNet Rookies judging by the logo in the upper left hand corner. In the clip A-Peace’s sub group Sky goes around offering free hugs.
On December 6, 2011 a music video was released for “A Ring Mark (반지자국)” This time it’s actually a music video with a story line and everything.
Getting back to A-Peace as a whole. On March 27, 2011 AllKpop reported that they were getting ready to debut in Japan, and after would return to Korea. A few interesting facts also reported by AllKpop are that all 21 members stand at or around 185 cm (about 6 feet) in height and were cast and produced by Kim Kyung Wook. If you don’t know him, he discovered and worked with idols like H.O.T, Shinhwa, and TVXQ. 
A-Peace has released two teasers for the song “Lover Boy (러버보이)”, but have yet to release a full music video that I can find.
First released was an audio teaser, released March 27, which is again, a photo shoot video.
The second is labeled as the “black version” teaser, which is again for the song “Lover Boy”, but with vocals now too. This one is, you guessed it, another photo shoot video, it shows some up close shots of the boys, and at 0:21 there’s some chocolate abs. This one was released April 1, 2011. 
There are a few other pictures on their twitter, including a photo of dance practice and one of the member’s abs.
In early March, A-Peace performed a live showcase on BBS Station with their song “Lover Boy”. 
They start with 5 members on stage, but soon the rest pour on as well. For such a large group their synchronization is pretty good.
“The group are set to embark on their music careers through Japan’s “K-Theater” before making their official debut in Korea.”
On May 12, 2011 A-Peace released their music video for “Lover Boy” 
Here’s the dance version:
**Last updated May 22, 2011**