In winter, it sold the privilege of lingering long enough to remember why people travel in the first place.… By the time people began calling it The Two Seasons Store, nobody remembered that it had once been dismissed as a foolish investment. The shop stood beside a crescent-shaped beach on Japan’s Pacific coast. During July and August, it barely had time to rest. Young drivers arrived in convoys from nearby cities, their navigation apps steering them to the same stretch of sand that had become popular on social media. They bought bottled water, sports drinks, electrolyte powders, frozen desserts, sunscreen, and disposable phone pouches before running toward the surf. Many stayed only a few hours. They coated themselves with tanning oil despite increasingly frequent public warnings about ultraviolet exposure, snapped photographs, and disappeared before sunset to avoid traffic. The owner, Aiko Fujimura, understood a truth that surprised accountants visiting from...