In Kitakami, a sleepy city deep in the countryside 500 kilometers north of Tokyo, Japan’s AI revolution is unfolding more as a slow burn than a boom.On a humid Friday evening in July, the city’s downtown hummed with activity as tech workers from Kioxia Holdings Corp.’s nearby chipmaking plant let off steam in bars and karaoke clubs. A few streets over, taxis crawled along the gravel of a road that’s being repaved to improve access to the factory after it opened a new production facility last ye...