"For the new stadium, I want to show wood, instead of concrete," says Kuma. "We are living in the postindustrial era, and we should show the beauty of wood."
"In 1964, I was aged 10," he says. "I was very much inspired by the event. My plan for the future was totally changed by the Olympics."
"The 2020 Olympics should show something for kids, should give great hope to kids. I think it's the big role of the Olympics," says Kuma.
The New National Stadium will serve as the main venue for the Games, but there are also other venues in and around Tokyo including places for soccer, sailing and surfing to name a few.
One of the main themes of the Games is to show the world Japan's recovery from the 2011 earthquake and tsunami.
So, the prefectures of Miyagi and Fukushima, which were devastated by the disaster, will also host some of the events.
Construction work is continuing on the stadium, with work on the roof expected to start in February next year.