During the first year, Esther Austin taught a class of 11 children in an unused building at the Far East Broadcasting Network's facility in Chatan.
The purpose of the school was broadened to include children of non-Christian and non-church-affiliated families in the first few years.
OCSI purchased land on "Hacksaw Ridge" in Urasoe City, a site of fierce fighting during the Battle of Okinawa in World War II.
Shortly after this expansion, OCSI celebrated its first commencement when the graduating class of 1969 received their high school diplomas.
By 1986, OCSI was looking to expand again, and by 1996 a new campus overlooking the East China Sea in Yomitan Village was purchased.