I doubt that having Rule as the theme song is going to do anything for Ayu's popularity overseas. It might rake in a few fans here and there but it's not going to be anything major or amazing.
Look at Utada-- Kingdom Hearts was super, super popular and Simple and Clean / Sanctuary were both in English, but all it did was create a larger fan base for her overseas.
I don't think Rule will do anything more than that for Ayumi and Rule probably won't gain her as many fans as Simple and Clean or Sanctuary did for Utada because...
a.) A lot of the times, people don't pay attention to the theme song (and if it's played in the credits and not the beginning, people will be leaving.)
Whereas in a video game setup like Kingdom Hearts you hear the song at the beginning and end of the game and for any fan of the game, it made the song a classic.
b.) Again-- it being in Japanese isn't going to spark as much curiosity. Americans, for the most part, just aren't interested in foreign music. Had Hikari been used for the American release of KH1, I can't say I would've looked it up. At the point I had never heard a Japanese song in my life.
Idk... I just think people seem to be either totally against this or way too excited about it.
I just wanna hear Ayu in the theater~
