Takagi is from Shirahama, Chiba and began judo when he was in junior high school.

[1] Takagi began working for the Tokyo Metropolitan Police Department after graduation from Nihon University in 1971.

As of 2011, Takagi coached judo at his alma mater, Nihon University.

Among his students are Jun Konno, Michiaki Kamochi, Makoto Takimoto and others.

This biographical article related to Japanese judo is a stub.