Since arriving in Japan in 2008, Apple Inc.'s iPhone series has won the love of many Japanese cellphone users long accustomed to phones heavily customized for the domestic market.

The iPhone shock could have even more repercussions, as the September debut of the iPhone 5 appears to be changing the landscape of Japan's telecommunications industry.

Softbank Corp. made a surprising move last week to acquire eAccess Ltd., the country's fourth-largest carrier and operator of the Emobile brand, to reinforce its network infrastructure and gain a competitive edge over its rivals, especially KDDI Corp. The competition between Softbank and KDDI — the two iPhone providers in Japan — has been escalating.