After university, he worked as a political reporter for Nippon Television, covering the Finance and Foreign Ministries and the Prime Minister.

He served as Minister of Land, Infrastructure and Transport from 2003 to 2004, and was chairman of the Highways Committee of the LDP Policy Affairs Research Council from 2005 to 2007.

[2] Following Prime Minister Yasuo Fukuda's resignation, Ishihara stood as a candidate for the LDP presidency.

[3] Ishihara was named as a potential LDP candidate for the 2014 gubernatorial election in Tokyo, but along with fellow LDP legislators Yuriko Koike, Tamayo Marukawa and Satsuki Katayama, performed poorly in a December 2013 poll against Yoichi Masuzoe and Hideo Higashikokubaru.

[7] After the elections, he was appointed an advisor to Kishida Cabinet, but he resigned after a week when it emerged that the local LDP chapter he headed, received government subsidies intended for businesses recovering from the COVID-19 pandemic.