Japanese mobile carriers NTT DoCoMo, SoftBank, and KDDI are all set to offer the 16GB version of the iPhone 5s for free with a two-year contract, marking the first time that all three major carriers in the country will carry Appleās flagship mobile device, reports CNET. Each carrier plans to offer the phone for free with discounts that enable the special pricing, with DoCoMo offering rewards points for users who bring in used iPhones from SoftBank or KDDI. Japanese business newspaper Nikkei [