There are many christmas songs that are sung in America and Europe and then has been translated into Japanese. Popular, or Carols.
Among them the one I like best is titled in Japanese Morobito Kozorite. I recently found in japanese Wikipedia that its music is the christmas carol “Joy to the World” but the lyric is translated from another one.
The japanese lyric is as follows:
Mo ro bito ko zo ri te (People all together)
Mu ka e ma tsu re (welcome and celebrate)
Hi sa shi ku (For a long time)
Ma chi ni shi (We had waited)
Shu wa ki ma se ri (The Lord has come)
Shu wa ki ma se ri
Shu wa shu wa ki ma se ri
The lyric is classical Japanese, which I could not understand when I first learned it in my childhood.
But I loved the melody and the sound of unknown words, as if they were of a foreign language.
Especially the last refrain “Shu wa ki ma se ri” has been always my favorite.
We sing it more likely as “Shoe wacky mass say lee.” (There’s no difference between r and l in Japanese)
As for “Joy to the World,” I also like the popular song of this title by Three Dog Night.
I liked the band very much in the year of ’70s, when I was 10 years old or so.
I often listened to their song “The Show must go on”, “Old Fashioned Love Song,” etc.
Then my favorite music changed to progressive rock and now heavy metal. But it’s not related to christmas songs, sorry.