What's 白ロム（shiro-rom）

When we buy cell,
①Combined sale（Japan Basic）-->cell＋carrier contract needed.
②Sim-free（World Basic）--> Basically,New one.but don't need carrier contact (EX.two-year contract).
③白ロム(Shiro-rom)---＞Used.and don't need carrier contact (EX.two-year contract).
④赤ロム（Aka-rom）---＞Used include having an outstanding debt（WARNING）

It's necessary for tourists to get 白ロム(Shiro-rom).but you have to seek for it Akihabara or Amazon.If you need iPhone, Apple store sell Sim-Free one.