When Prime Minister Shinzo Abe scrapped Zaha Hadid's design for the new National Stadium on July 17 last year, many feared the venue might not be completed in time to host the 2020 Tokyo Olympics.

Twelve months on, despite construction still waiting to start four years before the games begin, Hadid's replacement, architect Kengo Kuma, has no doubts the stadium will be ready.

"This is a rare case in Japan," Kuma told The Japan Times in an exclusive interview. "Usually in Japanese construction, first you have the plan and then, when that's finished, you begin construction.