Can you buy a US model phone in Japan?

I live in Japan and have no immediate plans to return to the US. Buying phones in Japan is a pain. My phone's screen is broken, it's not holding a charge, and it's slow and doesn't run most apps. I want to buy a new phone, but I don't want to change my contract (I have no contract) and I don't want a phone that can't be completely silent (pictures always make sounds on Japanese phones).

Is it possible to buy an American model phone in Japan? I tried asking a salesman, but apparently this is way beyond my Japanese ability and he just wanted to sell a phone with a carrier for a bonus.

Thanks!