Japan, like any jurisdiction, has its elite group of corporate law firms. Just as London has its Magic Circle, Tokyo has what Western media likes to call the Big Four: Nishimura & Asahi, Nagashima Ohno & Tsunematsu, Mori Hamada & Matsumoto and Anderson Mori & Tomotsune.

The gap between this dominant quartet and the rest of Japan’s legal market has always been seen as unbridgeable. But one firm, TMI Associates, is trying to challenge the status quo and make the Big Four a Big Five. And it’s making real headway.