You know how Beatles' song are insanely expensive to licence for movies, TV, commercials and all (to the point that the Lego Company couldn't even use the song "Yellow Submarine" to promote their very official Beatles set "Yellow Submarine")?
Well, either the Beatles estate is not aware that Japan exists, or for some reason the country got a special deal.
It seems that every other TV show has a Beatles song as music background... Interesting...