What happened with...
 

"Two TA fans will get the oportunity to record vocals for a new song to be released in 2013"

Yes, I'm talking of one of the special gifts of the 15th anniversary mess.

I think they're just playing with us.... like now. Where is Zutto...'s making off video stream?....

Giving me lady gaga vibes.
I always thought the recording thing was for Tell All.

Tell All was released on 4/8 though, and that's the date the winners were announced.

Twitter user mai_19890707 was one of the winners (the winners list was posted on Ayu's site, and yes two people are listed there.... Mai was the only one of the two I found anything about online). As of October 2013 she hadn't been called in to record, but I'm not seeing any updates since then that seem to refer to the recording.

Maybe they recorded it and Ayu gave the song to them only as a special treasure.

And nobody heard about it? Hard to believe.

Absence of Zutto making of is really surprising as if they forgot about it.

Perhaps they dropped this prize or just delayed it indefinitely?