Kaisei Academy

Kaisei Academy admits approximately 300 students to its junior high school and 400 to its high school each year. The school's motto is a tradition of 質実剛健 (shitsujitsugouken), a yojijukugo Japanese phrase meaning “strong and simple”. Its English motto is "The pen is mightier than the sword".

The school was founded in 1871 by Sano Kanae, a lecturer of Western studies, gunnery, and oceanography.^[2] Initially established as Kyōryū Academy (共立学校), the school was closed after Sano's death in 1877. In 1878, the school was reopened, and Takahashi Korekiyo, then a professor, became the first principal of the restructured institution, transforming it into a preparatory boarding school.^[3] In 1879, 112 out of 466 students were admitted to university.

The school was renamed Kaisei Academy in 1895.

• Keisuke Okada, (1868–1952) Prime Minister (1934–1936)
• Kikunae Ikeda, (1864–1936) Chemist who identified umami
• Hantaro Nagaoka, (1865–1950) Physicist who proposed the Saturnian model of the atom
• Masaoka Shiki, (1867–1902) Poet, one of the "four great masters" of haiku
• Tōson Shimazaki, (1872–1943) Poet and author, a leading figure in Meiji Romanticism
• Akiyama Saneyuki, (1868–1918) Admiral, planner of the Japanese strategy at the Battle of Tsushima
• Chikahiko Koizumi, (1884-1945) Surgeon Vice-General of Japan^[4]
• Tamon Yamaguchi, (1892–1942) Vice Admiral, commander of the aircraft carrier Hiryū at the Battle of Midway
• Toshirō Mutō, (born 1943) Former Deputy Governor of the Bank of Japan
• Fumio Kishida, (born 1957) Prime Minister (2021–2024)
• Takayuki Kobayashi, (born 1974) Chairman of the Policy Research Council in the Liberal Democratic Party
• Keisuke Suzuki, (born 1977) Minister of Justice (2024–2025)

• List of high schools in Tokyo