The move represents OgilvyOne stepping up its efforts in the region and follows recent expansion in other parts of Asia Pacific. In May, the agency launched into China for the first time.
The move also represents WPP's ongoing moves to expand its interest across a broad range of marketing services companies.
Earlier this year, WPP acquired a 75% stake in UK-based customer relationship firm QCI and acquired US marketing services company VML.
Landscape collects data on Japanese consumers, which is used by the direct marketing industry to more accurately target them. While direct marketing and customer relationship marketing practices in the West have become quite advanced, the Asia-Pacific market lags some way behind.
John Goodman, president of OgilvyOne Asia-Pacific, said, "This deal with Landscape is a good example of how the business is maturing in Japan. This is an unusual deal, if for no other reason than it's hard to find these kind of independent companies in Japan."
OgilvyOne is a sister agency to the Ogilvy & Mather Worldwide advertising network.