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

[Gustavopc]

I can't help but coming up with a conversation like this in my mind:

ayu: It's so nice to release this album at my 17th anniversary. It's been so long since I last celebrated my debut...
Staff: It's not been that much time tho
ayu: Of course it has, 2008 was eons ago
Staff: Well, there was your 15th back in 2013
ayu: My 15th?
Staff: Yeah, remember you released a special song called Tell All but never included it in your albums?
ayu: I did?
Staff: And there was that song which two lottery winners would sing the background vocals also
ayu: Wait, what?
Staff: So yeah, there were plenty of things back then
ayu: A song that didn't make to the album and fans to sing in a song... Well, I wonder if it's too late, but I've got some ideas...

And ta-daa here we are