I am currently using an iPhone 4 in the US on the AT&T network. However, I might possibly be moving to Japan soon. It was my assumption that if I unlock the phone I should be able to enter into a contract with Softbank and use my iPhone in Japan. However, during my short trip to Japan, I stopped by a Softbank store and asked this question to which the answer was no. It did not seem like the person knew too much as she was not able to answer a different question that I had, but is she correct in that I would not be able to use this iPhone that I purchased in the States? If there is a way, would you be so kind as to explain how I might be able to do so? Thanks!