Softbank is supposedly the most popular cell phone carrier in Japan. Which is apparent by how much they can spend on American celebrities to be in their ads. Cameron Diaz appears in a lot of their print and TV ads as you can see below.
Brad Pitt also does a bunch of ads too They recently added a new service tied to Disney called Disney mobile. Hillary Duff is the spokes women for the service. It’s a family friendly version of the normal Softbank service. People are crazy for Disney stuff over here, so this service should do well.
Softbank also has some really interesting TV ads featuring popular Japanese celebrity Ueto Aya, in which her family includes a father who has been changed into a dog, and a brother who is black. It a continuing series, and they have new ads every couple weeks or so. They are very strange and kinda funny. You can see a couple below. More can be seen here.