Tokyo's turbulent countdown

Another challenge is the athletes' village, expected to house 15,000 people from more than 200 countries and regions to compete in 33 sports at 42 venues.

The organizers have planned for 126,000 volunteers to shepherd athletes and spectators around the city.

"The medical system is already under strain. Our local health center can't possibly take care of those athletes in the village," said Hideki Hayakawa, director of the Olympic coordination unit at Tokyo's Chuo ward, where the village is located.