Sanae Takaichi became Japan's first female prime minister in October 2025, yet traders are pricing her as the most likely G7 leader to leave office next. Her odds jumped from 3¢ to 44¢ — a massive move that reflects growing concerns about political sustainability despite her recent electoral triumph. Takaichi's February snap election delivered a historic supermajority, the strongest for a Japanese government in over 70 years. But the market seems focused on structural vulnerabilities: her "one woman" governing style and tensions with coalition partner Nippon Ishin no Kai may be catching up with her. Reports of her intense work habits and health concerns add another layer of risk that traders appear to be pricing in aggressively.