St. Mary’s International School

St. Mary’s International School

St. Mary’s International School, founded by the Brothers of Christian Instruction, opened its doors to foreign boys ranging from kindergarten to grade three in 1954. Now its is an all-boy’s school with enrollment of nearly 1000 students in grades K-12 and are fortunate to have many opportunities for students to participate in the fine arts.

The primary language of instruction is English, but students from grade one study Japanese language with the opportunity for first language level in the high school. The school has a special commitment to language study and currently offers fourteen different second languages. The International Baccalaureate is well established in the high school on both the Diploma and Certificate level.

The school teaches and models the values of respect and tolerance in all of our classes and offer a K-12 Religion/Ethics Program that caters to boys of all beliefs and faith backgrounds to help them become true Global Citizens.

St. Mary’s entire campus is brand new and we are proud to say it is one of the safest buildings in Tokyo. The facilities include large, modern classrooms equipped with educational technology, a 25-meter swimming pool, a gymnasium that can host two basketball games at one time and a playing field that is second to none in the Tokyo area.

The extra-curricular programs are excellent: St. Mary’s Athletics includes basketball, baseball, tennis, soccer, swimming, wrestling and intramural opportunities. Our Fine Arts Department features drawing, painting, print-making, ceramics, photography, design technology and architecture classes. Performing Arts includes Fall Play, One-Act Play, Musical, Instrumental Music and our internationally recognized Choral Music Program. We also offer a variety of activities including speech, debate, Book Bowl, Brain Bowl, Cub Scouts and Boy Scouts, and others.


Kindergarden, Elementary School, Middle school, High school
03-3709-3411 (headmaster),
1-6-19 Seta, Setagaya-ku,Tokyo 158-8668
Accreditated by WASC & CIS; offers IB program; member of the JCIS and EARCOS.
  • St. Mary’s International School
  • St. Mary’s International School