NTT DoCoMo has partnered with Apple Inc. for the first time to offer iPhones in Japan starting Friday, September 20. Leading carriers including DoCoMo, SoftBank and KDDI (au) are giving away iPhone 5S for free with a two-year contract.

Japan's renowned mobile network carrier, NTT DoCoMo, lost a huge market share to rivals SoftBank and KDDI by not offering Apple's iPhone under its network over the years. But that is about to change now as Apple announced Tuesday that DoCoMo will offer its customers the latest iPhone 5S and iPhone 5C. The latest move will work in favor of both Apple and DoCoMo as most people in Japan fancy iPhones and choose the leading network for their wireless plans.

According to an earlier study by Kantar, two-thirds of DoCoMo subscribers who recently left the network went to rival carriers to buy an iPhone. By offering iPhones within the network will give the company an opportunity to regain the lost market share. To further attract customers, DoCoMo is offering 16GB versions of the Apple iPhone 5S to customers signing up for a a new two-year contract.

The free-for-all iPhone 5S deal also extends to KDDI (au) and SoftBank, who have been offering Apple iPhones for several years. All three companies announced the new offer on select plans, Friday.

The major reason for the delay in Apple and DoCoMo's partnership was due to Apple's  refusal to preinstall apps and services on the iPhones. DoCoMo preinstalls apps and services before it sells any smartphone. The network has its own online app store called dmarket, and their apps would have competed with Apple's iTunes, according to Bloomberg.

"NTT DOCOMO has built an impressive network, the largest in the nation with over 60 million customers," Tim Cook, Apple's CEO, said in a press statement, Tuesday. "We've enjoyed tremendous success with iPhone in Japan, in fact it's the top selling smartphone in the country, and we look forward to delivering iPhone into even more customers' hands through NTT DOCOMO."

The new deal is a big win for Apple as DoCoMo and China Mobile together could increase iPhone sales by 34 million next year, analysts predict. But the deal could affect the sales of local phone suppliers like Sharp and Fujitsu.