Willcom (株式会社ウィルコム) is a Japanese provider of personal handy phones, also known as PHS. Though a few more PHS phone services still exist, Willcom is expected to soon be the only remaining PHS service available in Japan.
PHS is, essentially, a limited mobile phone service that does not quite work as well as a cell phone due to poor roaming and limited travel distance but is far less expensive to operate. Because of the popularity of cell phones in Japan, PHS phones are becoming far less common and many manufacturers have begun to bow out of the PHS business. Because of that, Willcom is expected to be the only remaining PHS service in Japan within the year. It currently still has a very large revenue stream with over 4 million users and due to its recently released flat rate service, it has actually begun to see an increase in users (though this is substantially slowed due to cell phone popularity).
The company began as DDI Pocket and was a subsidiary of the KDDI corporation back in 1994. It was one of 3 companies that opened up PHS services, the other two being NTT-Personal and ASTEL. NNT-Personal has been taken by NTT-DoCoMo, so its PHS services are over, and ASTEL is said to be shutting down their services as well.
In 2005, DDI Pocket sold the majority share of their business to the Carlyle Group, an American organization. The group then changed its name to Willcom. KDDI currently only owns roughly 10% of Willcom now, with Carlyle owning 60% and Kyocera owning the remaining 30%.