Japan’s imperial family, which has long maintained a male-only lineage for emperors, is running out of royals. Now the country has a plan to help revitalize its dwindling ranks: Recruit more men. 日本皇室长期以来维持着仅限男性继承天皇之位的传统，如今正面临皇室成员后继无人的困境。现在，日本提出了一项计划以振兴日…