Japan’s DeNA loses a visionary of global mobile social network

Japanese game maker DeNA, which announced it was buying iPhone game maker Ngmoco for up to $403 million last October in a move to step out onto the global stage and build a global mobile social network, is losing its chief executive.

The company said today that its founder and chief executive, Tomoko Namba, is stepping down as head of the Tokyo company due to a family health issue. She will continue to play an active role in management as a board member and advisor.

Namba, who has an MBA from Harvard University, built DeNA from a small start-up in 1999 to a major mobile social game company on a billion-dollar run rate for revenues. She will be replaced by Isao Moriyasu, chief operating officer and general manager of its social media business. The move will be effective June 25, after the company’s stockholder meeting.

Moriyasu has led Mobage, the core social network of DeNA, since 2006. Namba said she believes he will be able to act quickly and decisively in the rapidly changing industry and make DeNA into a truly global company.

DeNA has more than 20 million users for Mobage-town in Japan and it has been expanding across multiple platforms. DeNA’s move into the North American market with the acquisition of Ngmoco prompted rival Japanese firm Gree to buy OpenFeint for $104 million.

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