I just got a Sim free iPhone 4s from oversea. In Japan, NTT Docomo user can’t use this normally due to not offering it from the company. So I and they need to arrange it originally.
And other carriers which provides iPhone 4S are SoftBank, and KDDI au.
They don’t offer network sharing service called “Tethering” on iPhone. But if you choice Docomo and sim free iPhone, we can use it.
In rumor, Docomo will provide it officially by the summer of this year.
I’m looking forward the official announcement.