When it comes to the future of work, Japan is caught in a tug-of-war. Tokyo officials are pushing for a four-day workweek, hoping a shorter schedule will ease the nation’s notoriously punishing work culture and curb “karoshi”—which translates to death from overwork. With birthrates falling and burnout rising, many see the shift not as a perk, but a necessity for Japan’s economic survival. But the country’s new prime minister, Sanae Takaichi, is signaling a very different approach. The 64-year-old drew scrutiny this month for summoning staff to a meeting at 3 a.m.—not for a national security crisis, but simply to...