St. Mary's International School: 2026 Guide to Reputation, Fees, University Placement, and Admissions

"An all-boys international school? Is it strict? What about university placement?"

In a world where co-educational international schools are the norm, St. Mary's International School (SMIS) stands out as one of the few all-boys schools in Tokyo.

However, it is not a 'jock-centric, spartan' institution. It is a college-preparatory school that balances a holistic education designed around the developmental needs of boys with IB results that surpass the global average.

In this article, ELT, as professionals in English and international education, provides a clear, fact-based overview of St. Mary's reputation, fees, university placement, admissions, and eligibility, based on official school data and our own support experience.

1. What is St. Mary's? An All-Boys International School in Setagaya, Tokyo

St. Mary's, founded in 1954, is a Catholic all-boys international school in Setagaya, Tokyo. It is a non-profit educational institution, accredited by WASC and CIS, and offers the IB Diploma Programme.

St. Mary's International School was founded in 1954 and relocated to its current campus (1-6-19 Seta, Setagaya-ku, Tokyo) in 1971. It is one of the few all-boys international schools in Tokyo. Rooted in the Catholic tradition, it provides a seamless education from the Readiness Program (RP, equivalent to kindergarten, for age 5) through to Grade 12 on a single campus.

It's important to understand the school's official status. St. Mary's is operated by a non-profit educational institution, but it is not an "Article 1" school under Japanese law. Instead, it is classified as a private "miscellaneous school" (kakushu gakko) by the Tokyo Metropolitan Government (this distinction can be significant for some families and is detailed in Chapter 6). While its origins are with the Catholic teaching order (Brothers of Christian Instruction), religious faith is not a requirement for admission, and the school welcomes students from all backgrounds.

The school holds extensive international accreditations and memberships. It is accredited by the Western Association of Schools and Colleges (WASC) and the Council of International Schools (CIS, re-accredited in 2024), and has been an IB World School (code 000134) since 1979. It is also a member of the International Boys' Schools Coalition (IBSC), EARCOS, and university admissions organizations like NACAC and International ACAC, as well as the American Choral Directors Association (ACDA).

Basic Information

2. The Purpose of an All-Boys School: Boy-Friendly Learning and Holistic Education

St. Mary's officially states its mission is to "design learning to meet the developmental needs of boys," providing a holistic education that encompasses their spiritual, moral, artistic, athletic, and academic growth.

"Why choose an all-boys school today?"

St. Mary's answer lies not in tradition, but in educational design. The school's official Guiding Statements articulate the belief that an all-boys environment facilitates learning tailored to boys' developmental needs. The "Understanding by Design" framework is used consistently from RP through Grade 12, promoting a holistic education (educating the "whole child") that encompasses spiritual, moral, artistic, athletic, and academic development.

Specifically, this approach has the following characteristics:

First, a culture where boys can immerse themselves in activities without the social pressures of a co-ed environment.

Boys who might shy away from choir or drama in a co-ed setting often dive into the arts with passion at St. Mary's. In fact, over 90% of high school students participate in Fine Arts & Activities. The school boasts acclaimed music programs (choir and band), a thriving Model United Nations (MUN), speech and debate teams, and popular video and design clubs. Athletically, from its traditional wrestling team to other sports, the school has a strong record of success in Kanto Plain and Far East tournaments.

Second, a strong sense of vertical bonding (Brotherhood).

With students from age 5 to 18 on the same campus, older students naturally mentor and look out for younger ones, fostering connections across age groups.

Third, the values of a Catholic school.

The school promotes RESPECT, INTEGRITY, COMPASSION, RESPONSIBILITY, COURAGE, and HARMONY, nurturing character through service activities and other programs.

This is not to say that an all-boys education is inherently superior. St. Mary's official position is simply that it designs its education to align with the developmental traits of boys. For families who place a high value on the diverse social interactions of a co-educational environment, other schools may be a better fit (as compared in Chapter 6).

3. IB Results and University Placement: Exceeding Global Academic Standards

Nearly all high school students at St. Mary's take IB courses, with approximately 88% pursuing the full diploma. The school's average IB score consistently surpasses the global average, and graduates go on to universities in the UK, US, Canada, Australia, and Japan.

While often perceived as a "sports school," St. Mary's academic achievements are among the best in Tokyo.

In High School (Grades 11-12), nearly all students take IB courses, with approximately 88% undertaking the full diploma (3 HL + 3 SL subjects).

IB Diploma Results (Source: School Profile 2025-2026, last 3 years)

With a maximum score of 45, the school's average is consistently 3-5 points above the world average, with a top score of 44 in each of the past three years. The percentage of students earning a Bilingual Diploma ranges from 38% to 52%.

The school has strong offerings in the sciences. Group 4 subjects include Biology, Chemistry, Computer Science, Design Technology, and Physics, while Group 5 offers Mathematics (Analysis & Approaches and Applications & Interpretation). The mean SAT score for the Class of 2026 (as of August 2025) was 1345, with a middle 50% range of 1300-1450.

University Placement (Destinations for Class of 2025 + Matriculations from 2021-2025)

Let's look at the university destinations for graduates, based on data from the official School Profile.

The destinations by region for the Class of 2025 were: USA 35%, Japan 27%, Canada 12%, UK 12%, Oceania 8%, Europe 3%, and Asia 3%.
While there is a strong international focus, approximately a quarter of students matriculate to Japanese universities (often through English-track or returnee admissions).

The following is a list of select universities where graduates have matriculated between 2021-2025 (cumulative, including multiple acceptances):

• UK: University of Oxford, Imperial College London, UCL, King's College London, LSE, University of Edinburgh, University of Warwick, University of Bristol, University of Bath, University of Manchester, University of Leeds, University of St Andrews
• USA: Brown University, Dartmouth College, UC Berkeley, UCLA, UC San Diego, University of Michigan, University of Pennsylvania, University of Chicago, NYU, Northwestern University, Boston University, Rice University, Georgia Institute of Technology, Purdue University, Rhode Island School of Design, Berklee College of Music
• Canada: McGill University, University of Toronto, University of British Columbia
• Japan & Asia: The University of Tokyo, Keio University (GIGA/PEARL), Waseda University, Sophia University, ICU, Osaka University, Ritsumeikan APU, National University of Singapore (NUS), The University of Hong Kong, HKUST, KAIST
• Oceania: The University of Melbourne, The University of Sydney, Monash University, The Australian National University (ANU)

*Note: This is a cumulative list of matriculations from 2021-2025, not the results of a single year. A key feature of SMIS is the diversity of student pathways, from the arts (music, design) to engineering and medical sciences.

Comprehensive University Counseling

University counseling begins in Grade 10. The process includes aligning PSAT results with IB subject choices in Grade 10, retaking the PSAT and holding family meetings with assigned counselors in Grade 11, and receiving hands-on application support in Grade 12. The school also hosts an annual Career Day with alumni. Notably, St. Mary's limits students to 12 university applications worldwide, encouraging a strategic and focused approach.

4. What are the School Fees at St. Mary's? First-Year Total Cost (2026-27)

For the 2026-27 school year, annual tuition at St. Mary's is ¥2.86 million for Elementary School, ¥2.97 million for Middle School, and ¥3.05 million for High School. Including one-time fees, the total first-year cost ranges from approximately ¥4.51 million to ¥4.70 million.

Tuition and Fees (2026-27 Academic Year, Official)

Estimated First-Year Total Cost

The first year has the largest financial impact due to one-time payments (Registration and Development Fund). Based on mandatory fees, the estimated total first-year costs are as follows (bus, device, and IB exam fees are separate):

• Elementary: Approx. ¥4,510,000
• Middle: Approx. ¥4,620,000
• High: Approx. ¥4,700,000
• (Calculation = Application Fee + Registration Fee + Development Fund + Building Maintenance Fee + Tuition)

For returning students, a Re-Enrollment Seat Deposit of ¥300,000 (which is applied toward tuition) is required to secure a place for the following year. Therefore, the effective annual cost for subsequent years is the sum of tuition and the building maintenance fee. Please note that information on scholarships, financial aid, or sibling discounts was not available on the school's official fees page (though a Corporate Contribution Program is mentioned). For detailed information on fees, please contact the school's business office directly.

5. Admissions and Transfers: The Grade 1 Process and Transfer "Hurdles"

The admissions process at St. Mary's varies by grade level. For Grade 1, the process includes an autumn application, screening tests, a group observation, and a parent-child interview. Transfers are considered on a rolling basis, but the school does not accept students into Grade 12, and English language support is typically limited to students up to Grade 8.

Grade 1 (Main Entry Point)

Entry into Grade 1 is the main intake year with the most available spots. The general process is as follows:

1. Application (Autumn): Applications are submitted between early September and late October of the year before entry. A confidential recommendation from the current preschool/kindergarten teacher and records from the past two years are required.
2. Screening Test (Early November): A 30-minute, iPad-based test (similar to MAP) that assesses age-appropriate math concepts and English listening skills.
3. Group Observation (Mid-November): Applicants participate in group activities like playing with blocks or drawing, where assessors observe their social skills and ability to follow instructions.
4. Parent-Child Interview (Early December): An interview in English with the principal to ensure the family's educational philosophy aligns with the school's mission.
5. Admissions Decisions (Late January).

Transfers (Grade 2 and Above) and Their "Hurdles"

Transfers for Grade 2 and above are handled on a rolling admissions basis, with selection based on MAP tests (Math & English), an English essay, and an interview. However, there are several key institutional constraints to be aware of before applying:

• The school does not accept transfer students into Grade 12.
• To complete the full IB Diploma Programme, students must enroll by the beginning of Grade 11 at the latest to complete the two-year program at SMIS.
• English as an Additional Language (EAL) support is offered from RP to Grade 8. It is limited in Grades 9-10, and no EAL support is available from Grade 11 onwards. This means that students transferring into the upper grades are expected to have near-native English proficiency to keep up with coursework and discussions.
• If a grade level is full, applicants may be placed on a waitlist. Placement is not first-come, first-served but is based on the results of the screening process.

Planning for a transfer in the upper grades or timing entry for the IB Programme requires careful, individualized planning, so early preparation is advantageous. For help with MAP, interview, and English preparation, please see our guides on Interview Prep and MAP Test Prep.

"When and how should my child apply?"

ELT's free counseling can help you create a clear roadmap for application timing and preparation.

[Important] Eligibility for Japanese Nationals

Due to these requirements, applicants who hold only Japanese nationality are not automatically eligible to apply. According to the St. Mary's admissions policy, they may be considered for admission if they meet one of the following criteria:

• The student has recently been educated in a school where English is the primary language of instruction, with at least one year of attendance for elementary/middle school applicants or two years for high school applicants.
• The student has an English-speaking parent of foreign nationality (expatriate parent).

After enrollment, students are required to reside with a parent or guardian who holds a valid visa for Japan. Families of Japanese nationality are strongly advised to contact the school directly to confirm their eligibility before applying.

Comparison with Other Major International Schools in Tokyo

Let's compare St. Mary's with other major co-educational schools.

[Expert Advice on Choosing a School]

St. Mary's is a good fit for families who: Prefer an all-boys environment / Want a balance between the IB curriculum and strong extracurriculars (sports, arts) / Can plan for their son to enroll by Grade 11 to complete the IB DP / Want to nurture their son's strengths in math, science, and STEM.

For a broader comparison of international schools in Tokyo, please refer to this article.

Summary: What Kind of Student is St. Mary's Best For?

St. Mary's International School is more than just an "English-speaking environment." It is a school that combines an educational design that leverages the strengths of boys, academic results in the IB Programme that exceed the global average, and deep offerings in both athletics and the arts.

It is a compelling choice for a boy who:

Is interested in math, science, or STEM.

Would thrive when encouraged to commit seriously to a passion.

Benefits from a structured and disciplined environment.

At the same time, families should be aware of the practical considerations early on: its status as a non-Article 1 school, the specific eligibility requirements for Japanese nationals, the inability to transfer into Grade 12, and the significant first-year costs. It is wise to evaluate the school's educational appeal separately from these institutional and financial factors.

ELT provides support for every stage, from building a foundational English ability and preparing for admissions tests like MAP and interviews, to long-term planning for the IB Programme and university applications worldwide.

"Is this the right school for my son?"

"When and how should we apply?"

If you have these questions, please don't hesitate to contact ELT for a consultation.