In Tokyo you can't escape the American celebrities in T.V. commercials and billboards. From Tommy Lee Jones (for Boss Coffee), to Brad and Cameron (for phone operator Sofbank), and George Clonney (for anything he can put his face on, Honda, Toyota, Nespresso...) they are everywhere.
Besides the big celebs Japan also has a tendency to randomly pick (no offense to anyone) slightly less well known people, like let's say, French singer Alizee for a cookie ad, or recently, Emmy Rossum for Mt.Rainier Caffe Latte. Probably inspired by Scarlett Johansson's horrible Starbucks commercial (sorry I could not find it), Mt.Rainier decided to find itself a star as well and ended up with Emmy. I don't know if it's to pay for acting school or to prepare Japan for her role in the upcoming Dragon Ball movie (so instead of wondering who's that girl playing Bulma, they will say: oh, that's the girl from the Mt.Rainier ad) but in any case it's priceless.
Here's Emmy looking like she's having an awesome time drinking lattes and dancing.

Definitely looked like a fun party.

Go Emmy, I hope we'll see more of you soon.

Here's Emmy full performance
here or
here. I think I liked The Phantom of the Opera better.