Musashi Junior and Senior High School
is a privately owned school for boys based in Nerima, Tokyo, Japan.

History 
The school was founded in 1922 by prominent industrialist Nezu Kaichirō, as Musashi High School. The school was one of the first institutions of its type to use a seven-year system of education, taking students up to the equivalent of the first two years of university under the current system of education. Musashi became a prototype for the modern integrated junior and senior high schools that now prevails throughout Japan. After the education reforms of 1948, the school was divided into Musashi Senior High School and Musashi Junior High School. Musashi University was founded in 1949 and forms part of the same legal entity.

Admissions
The school operates a highly selective admissions program attracting students from across the city. Graduates have been successful in gaining admission to many of Japan's most selective universities. The school is unusual in the fact that it has few written rules and has no uniform or required dress code; reflecting one of the school's founding principles being that it aims to produce graduates that are "individuals", "capable of independent thought and research." 

All students start learning a second foreign language in junior high school in addition to English.   

The school shares a number of library and campus sporting facilities with Musashi University.

Notable alumni 
Kenkichi Iwasawa (1917–1998) Mathematician, Cole Prize
Morikazu Toda (1917-2010) Physicist
Kiichi Miyazawa (1919-2007) Prime Minister 1991–1993.
Shōichi Saba (1919-2012) former CEO of TOSHIBA
Hiroshi Miyazawa (1921-2012) Minister of Justice 1995-1996.
Shinya Inoué (1921-2019) Biophysicist
Hiroomi Umezawa (1924-1995) Physicist
Tsuneo Tamagawa (1925-) Mathematician
Akito Arima (1930-) Physicist, Minister of Education 1998–1999.
Eiiti Wada (1931-) Computer-scientist
Yoshinobu Nishizaki (1934-2010) Film producer
Ken Itō (1935-) Composer
Taizo Nishimuro (1935-) CEO of Japan Post Holdings
Naoki Tanaka (1940-) Minister of Defence 2012.
Hiroshi Hoketsu (1941-) Equestrian
Isao Sasaki (1942-) Actor
Toshitsugu Saito (1944-) Politician, Director General of the Defense Agency 2000-2001.
Tamio Kageyama (1947-1998) Novelist
Toshiro Fujita (1948-) Physician-scientist
Yoshitsugu Harada (1952-) Politician
Takeaki Matsumoto (1959-) Politician, Minister of Foreign Affairs 2011.
Seiji Kameda (1964-) Music producer
Masahiko Shibayama (1965-) Politician, Senior Vice-Minister for Internal Affairs and Communications 2012-2013.
Seiji Kihara (1970-) Politician, Senior Vice-Minister of Foreign Affairs 2015-NOW.