With waves, smiles and high fives, but no cheers, the Olympic torch relay set off on Thursday, beginning a four-month countdown to the postponed 2020 summer Games in Tokyo, the first ever organised during a deadly pandemic.
Casting a pall over celebrations already scaled back because of coronavirus prevention measures, North Korea launched two short-range ballistic missiles before the relay began in Fukushima, an area hit hard by the 2011 earthquake, tsunami and nuclear disaster.
"For the past year, as the entire world underwent a difficult period, the Olympic flame was kept alive quietly but powerfully," Tokyo 2020 president Seiko Hashimoto said at the opening ceremony, which was closed to spectators.
"The small flame did not lose hope, and just like the cherry blossom buds that are ready to bloom, it was waiting for this day," Hashimoto said.
Authorities have decided foreign spectators won't be allowed in stadiums, and it remains undecided how many Japanese will be allowed to attend.
With organisers billing the games as the "Recovery Olympics," a nod to the disaster as well as the pandemic, Thursday's runners included many who had fled after the meltdowns at the Fukushima Dai-ichi power plant.
Japan has fared better than most countries, with about 9000 coronavirus deaths, but Tokyo reported 420 cases on Wednesday, the highest single-day figure this month.
Polls show the majority of the public is against holding the Olympics as scheduled.
About 10,000 runners will take part in the four-month relay, which will go through all of Japan's 47 prefectures.
The relay, which will culminate with the Olympic opening ceremony on July 23, has been hit by several high-profile runner cancellations as celebrities and top-level athletes have pulled out, citing late notice and worries over the pandemic.
The brief, solemn opening ceremony, closed to the public, was held at J-Village in Fukushima, a sports complex converted for several years into a staging ground for workers decommissioning the crippled nuclear power plant.
Low-key events featuring Fukushima residents in drum and dance performances were followed by a children's choir before the Olympic flame, flown in from Greece last year and kept alight under 24-hour guard, was used to ignite the torch.
Members of the Japanese national women's soccer team were the first group to run with the flame, wearing white uniforms decorated with red.
The number of spectators, some waving Olympic flags or carp-shaped cloth streamers, increased throughout the day, ranging from nursery school children in colourful caps to elderly people clapping in front of flowering spring trees.
Some runners grinned and posed as they handed off the torch, waving, while others set off to the beat of traditional Japanese drums. One man pushed himself in a wheelchair, the torch mounted in a bracket.
Most spectators kept some distance from each other and there were mainly muted claps. Organisers have said the relay will skip areas that are too crowded, or pause until people disperse.