Takemi used to be a professor of Tokai University whose main subject is international politics.

He served until July 2007, and was Vice Minister of Ministry of Health, Labour and Welfare of the Abe Cabinet from September 2006 until August 2007.

[2] From 2012 to 2014, Takemi served on the High-Level Task Force for the International Conference on Population and Development, co-chaired by Joaquim Chissano and Tarja Halonen.

[3] In March 2016, Takemi was appointed by United Nations Secretary-General Ban Ki-moon to the High-Level Commission on Health Employment and Economic Growth, which was co-chaired by presidents François Hollande of France and Jacob Zuma of South Africa.

[5] Since 2022, he has been a member of the Commission for Universal Health convened by Chatham House and co-chaired by Helen Clark and Jakaya Kikwete.