Japan's Taro Kono, a former foreign and defence minister currently leading the vaccine rollout, announced his run for the leadership of the ruling Liberal Democratic Party on Friday.
One of the country's most recognisable political figures, Kono is a top contender for the post, up for grabs after Prime Minister Yoshihide Suga said he would not stand.
Whoever wins on September 29 will lead the party into general elections in October or November, and Kono said he was running to "move Japan forward".
"Japan may seem to be standing still, while other countries are trying to actively move forward. Maybe once Japan was in a top position, but unfortunately now we are maybe no longer a front-runner," he said.
"We must push the heavy door in front of us and open up our path forward."
Kono, currently minister for administrative reform, said he wanted to boost Japan's tech prowess through smart grids and 5G, and hit out at government bureaucracy that he said had slowed vaccination.
He also said the country needs to wean itself off coal and petroleum to achieve its 2050 goal of carbon neutrality, upping renewables and keeping the option of nuclear if necessary.
The 58-year-old minister, believed to have Suga's support, has two rivals so far: former foreign minister Fumio Kishida and hawkish female LDP member Sanae Takaichi.
Once seen as a maverick, including for his formerly staunch anti-nuclear position, Kono has recently toned down his rhetoric.
He is an experienced politician who was foreign minister between 2017-19 during a period of rapid deterioration of ties with South Korea.
He then held the defence portfolio, famously opting to scrap deployment of a pricey and controversial missile defence system.
Kono is a Georgetown graduate, a fluent English speaker and a keen Twitter user, embracing memes and regularly engaging directly with the 2.3 million followers of his Japanese account.
But he also has a reputation for being abrasive, and has been criticised for blocking people on Twitter as well as reportedly dressing down bureaucrats over perceived shortcomings.
He has championed efforts to digitalise Japan and end the use of fax machines and ink stamps in bureaucracy, while his appointment to oversee Japan's vaccine rollout has made him one of the most important faces in the country's pandemic response.
Some have questioned whether the rollout's slow start and occasional supply bumps could hurt him, but others believe that with around 50 percent of the country now vaccinated, he stands to benefit from his time in the post.