Entrepreneurs and entrepreneurship played a critical role in transforming Japan’s telecommunications sector. Between the mid-1990s and mid-2000s, in a sector long dominated by a stable set of large actors with well-established patterns of interaction, entrepreneurs introduced new technologies, new business models, and new norms of interaction. The subsequent transformation of Japan’s telecommunications sector was dramatic, providing consumers with not only fast and sophisticated services but also low prices and an entire new ecosystem of mobile content—a considerable departure from Japan’s long track record of being known as producer- rather than consumer-oriented, with consumers enjoying high-end services and products, but at high prices. Yet, these transformative entrepreneurs were not acting in a vacuum. Regulatory shifts in telecommunications were critical in providing opportunities for entrepreneurs, while simultaneously protecting them from large incumbent firms. These regulatory shifts were driven by the political dynamics of the 1990s as Japan struggled through its post-bubble economic malaise and political changes.