[8] It first opened as a supplementary school, with four teachers and 20 students, in the Convent of Our Lady Sion in September 1965.

It was upgraded to an official supplementary school in 1974 when the Japanese Ministry of Education sent its first teacher; it had done so due to an increase in the student body.

The Japanese Ministry of Education had sent Katsuya Tanaka, the first headmaster, to London the previous April.

[12] In 1988 the company Wilmott Dixon Western did a renovation on the school facility, adding two rooms for science classes and seven other classrooms, with work scheduled to be done by May 1989.

", wrote that "even company movers do not necessarily put their children through the Japanese schooling system in London" and several British and international schools in London cater to Japanese students.

In 1999 within the Saturday school there were 98 children of mixed British and Japanese heritage who came from mostly Anglophone homes.

[4] In 1991 teachers of the day school were sent by the Ministry of Education of Japan for secondments (terms of temporary transfer) of three years.

[14] The school has a system of buses that picks up and drops off Japanese students living in various areas in London.