In 1934 and 1938, the addressing system along the Koshu-Kaido was reorganized, creating the 6 chomes subdivision for Kōjimachi that are still used.

This place is also known for being the birthplace of Hideki Tojo, general of the Imperial Japanese Army and Prime Minister of Japan during the Second World War.

Chiyoda Board of Education [ja] operates public elementary and junior high schools.

Kōjimachi 5-6 chōme are zoned to Banchō Elementary School (番町小学校) in Rokubanchō.

[5] Chiyoda Ward operates Kojimachi Junior High School (麹町中学校) in Hirakawachō.