If Shinjiro Koizumi becomes Prime Minister of Japan as a result of government formation following the 2026 Japanese House of Representatives election and meets all constitutional requirements before Feb 8, 2027, then the market resolves to Yes. The person must be formally appointed, sworn in, or invested according to the country's constitutional procedures and command the confidence of the parliament/legislature through an investiture vote, formal approval, or constitutional convention. They must exercise the full powers of the office, not serve in a caretaker or acting capacity from the previous government. The appointment must stem from the government formation process following the specified election. Serving as caretaker pending government formation, being designated to form a government but not yet invested, leading the party with most seats without forming government, being named as designate without completing constitutional requirements, or holding the position temporarily during coalition negotiations do not satisfy the Payout Criterion. If no government forms by the deadline, all markets resolve to No except "No one" if that option exists. If new elections are called before government formation, markets resolve immediately. For rotating arrangements, the first person to meet all criteria resolves to Yes. If the person leading a party dies before taking office, their market resolves to last fair price and their successor may resolve to Yes. Markets for persons not explicitly listed resolve to "Other" if that option exists. This market will close and expire early if a person is formally appointed and invested as Prime Minister.