SoftBank Mobile
Japan's Ministry of Internal Affairs and Communications has legislated that all smartphones and tablets released after May 1, 2015, by NTT DoCoMo, au/Okinawa Cellular and SoftBank Mobile (the three major carriers in Japan) must be sold without a SIM lock upon request from customers and without any cost to the customer involved. Before that, from 2011 until 2015, only NTT DoCoMo and au/Okinawa Cellular would remove the SIM lock from phones with a SIM unlock function after the phone is kept or used at least six months after purchase.