New Delhi, Jan. 9 -- U.S. voters aren't the only ones up in arms about affordability.

Japan has cast off lost decades of deflation to join the rest of the developed world in modest inflation, currently running near 3%. That has been good for stocks, as companies recovered long-lost pricing power and banks could earn net interest margin.

Ordinary Japanese worry about their incomes keeping pace. "Real disposable income has hovered around zero in recent years," says Shigeto Nagai, head of Japan economics at Oxford Economics.

That angst was a big reason why 64-year-old Sanae Takaichi surged from dark horse to Japan's first female prime minister in October. She has flipped the script with strategically targeted spending hikes and tax cuts, ...