Remember the 15th anni. lottery prize of singing in the chorus of a song? [dwango.jp]

[lastminute]

I guess their voices were heavily edited or something because you can't really tell there are other people singing besides ayu. Also, they were background vocals so, it isn't supposed to stand out, really.
Anyway, the mere fact of being credited as background vocals on an ayu songs is beyond amazing. I really hope they got to meet her!!

Also, I guess avex made them sign a confidentiality agreement, it must have been so hard to keep The Show Must Go On a secret for what, 3 months?