You all realize that this thread is over a year old, right?

Anyways, in an old article, Ayumi says the song apparently came about because her producer was like, "Let's write a Christmas song" and they thought about it for a while (even sent out pleas to others to write the music, but in the end Ayumi/CREA was credited for it) So, I think any claims that Ayumi is Catholic or Christian just because of this song are most probably wrong.