The six years in junior and senior high school are important for the formation of personality. Both heart and mind, the foundation for love and intelligence, are formed through communication with teachers and friends.

Since the founding of the girls' school in 1905, Joshi Seigakuin has consistently practiced the educational philosophy of human education based upon Jesus Christ. In particular, the school motto, "Love God and Serve His People," is a symbol of our attitude of trying to find ourselves, precious and loved by God, and giving of ourselves.