刚刚！高市早苗当选日本首相！日股回落！

Group 1 - The core point of the article is the election of Sanna Takichi as Japan's first female Prime Minister, marking a significant milestone in Japanese politics [1][2]. - On October 21, Sanna Takichi received more than half of the votes in the first round of the House of Representatives' Prime Minister nomination election, becoming Japan's 104th Prime Minister [1]. - The House of Representatives holds priority in legislative and Prime Minister appointment decisions, and in case of disagreement with the House of Councillors, the House of Representatives' nomination prevails according to the Japanese Constitution [1]. Group 2 - Following the election, the entire cabinet led by former Prime Minister Kishida resigned, indicating a complete transition of power [2]. - Sanna Takichi has a long political career, having served in various significant roles including Minister of Internal Affairs and Communications and Minister for Economic Security, and is known for her close ties to former Prime Minister Shinzo Abe [2]. - The Nikkei 225 index showed a strong performance in the early trading session, approaching 50,000 points, reflecting market optimism following the political change [3].