Tokyo, once ahead in tech before being overtaken by Silicon Valley, is now trying to reinvent itself as a global startup hub by leveraging its stability, AI potential and government-backed support for entrepreneurs. | Getty Images

There was a time when Tokyo felt light years ahead of the world. The flip phone I used in the 2000s was a marvel to every American I showed it to, packed with features far beyond anything on the U.S. market.

But during the smartphone and internet era, Silicon Valley pulled ahead. Tokyo’s edge dulled as the country struggled through its lost decades and lagged in the shift from hardware to software. Now it’s trying something more ambitious than just catching up — it wants to become the most startup-friendly city in the world.

That push is led by Gov. Yuriko Koike, who has run the world’s largest metropolitan area since 2016.…