Sitting in his ramshackle Tokyo office filled with the stench of cigarette smoke and the leftover decor of the Chinese restaurant it was before, Taisuke Ono is the unlikely face of a populist wave that has upended Japanese politics.

The 47-year-old former Accenture consultant lost out in Tokyo’s gubernatorial race last year but has made a stunning comeback with the success of Nippon Ishin no Kai, or Japan Innovation party. In last week’s general election, the Osaka-based regional party shattered all expectations to become the country’s third-largest political force.

With a near quadrupling of its representation to 41 seats in the Diet’s powerful lower house, the once fringe party can provide Japan’s ruling bloc with the necessary votes if the government decides to push ahead with a revision to Japan’s pacifist constitution.