In 1853, the end of the troubled Edo Period, in the Nishiebara neighborhood the young peoples’ mind, culture confusion, dreams have all been lost. The family of Ichibashi’s Representative Katsuharu Tomiyama raises to realise the dream of private education in the area, therefore it’s the beginning of establishment of Kojokan.
The First Director, Mr. Akira Sakatani who gave his name as President of private school “Sakura Ridge” in Yoshii Village. While struggling with its financing, Ichinomoto school started as "Kanaka School". Since Koga Chichi (a child of the former teacher) who dropped by on the way from Edo to Nagasaki who left the rhetoric of "Kojokan", he gave the school's name "Kojokan".
Only 10 years since school opening, students from the Sangyo Area have come to study in Chukoku, Shikoku and Kyushu and which has created the name “ The World Three Hall”. (Mito Hiromichi Hall, Hagi Meikyukan, Okayama Koganekan), Schools. Teacher Sakatani is also known as Song-Sect Inner Sea who is world renowned.
Since then, for about 160 years, Kojokan has been the driving force for regional education. Many traditional and township schools tried to transform themselves into public school due to the dissemination of Meiji Academic system, but Kojokan continued to inscribe its history as semi-government private school and now as a high school in the country. By setting as a condition that the name of the school cannot be changed, it is now known as the oldest school in the country.