St. Mary's International School

"St."

Mary's International School is a private international school for boys situated in the Setagaya ward of Tokyo, Japan. Founded in 1954, the school has built a long and respected history in Japan's international education community, making it one of the more established institutions of its kind in the country. Its enduring presence in Tokyo speaks to a consistent commitment to delivering a rigorous, English-language education to the families of expatriates, diplomats, and internationally mobile professionals who call the city home. The school serves students across a full K–12 span, organized into elementary, middle, and high school divisions, all of which are housed on the Setagaya campus. This unified campus model means that boys move through their entire school journey within a single, cohesive community, allowing for strong continuity in relationships between students, faculty, and families. For parents navigating an international relocation, the convenience and consistency of a single-campus school covering all grade levels can be a meaningful practical and emotional advantage. English is the primary language of instruction throughout the school, making St. Mary's a natural fit for English-speaking families arriving in Tokyo, as well as for non-English-speaking families seeking full English immersion for their children. At the high school level, the school offers the International Baccalaureate Diploma Programme, one of the most widely recognized university-preparatory credentials in the world. The IB Diploma is valued by universities across North America, Europe, Asia, and beyond, making it a strong choice for families who anticipate further international moves or whose children may pursue higher education in multiple countries. What sets St. Mary's apart in Tokyo's competitive international school landscape is its singular focus on boys' education. A boys-only environment can offer distinct advantages, including a classroom culture tailored to how boys learn and engage, freedom from certain social pressures, and opportunities for young men to develop confidence, leadership, and voice in ways that coeducational settings may not always foster as directly. For families who value or have experience with single-sex education, St. Mary's offers that tradition within a thoroughly international context. The school's location in Setagaya, one of Tokyo's largest and most residential wards, places it in a quieter, greener part of the city relative to central Tokyo. Setagaya is a well-established area popular with expat families precisely because of its livability, access to parks, and strong community feel, while still being well connected to the broader metropolitan area. For relocating families evaluating their options in Tokyo, St. Mary's International School represents a well-established choice with deep roots in the city, a globally recognized academic credential at the senior level, and a clear educational philosophy built around the development of boys from kindergarten through graduation. Families are encouraged to visit the school's website at smis. ac. jp and to reach out directly to the admissions team to learn more about the community and what the school can offer their son.