Seisen International School vs Tokyo International School
🇯🇵 Tokyo · Side-by-side comparison on verifiable public data.
Neither Seisen International School nor Tokyo International School sits in a market with a public inspectorate, so both are assessed on verifiable accreditation, curriculum authorisation, and published data rather than an official quality rating. Both run the same curriculum (IB), so the differences come down to pathway detail, campus culture, and specific language/boarding arrangements rather than the curriculum framework itself. Both are day schools with fees in the same market band — see the table below for the figures, and verify against each school's own published fees.
Key Facts
| Seisen International School | Tokyo International School | |
|---|---|---|
| Curriculum | IB | IB |
| Ages | 2–18 | 4–17 |
| Languages of instruction | English | English |
| Annual fees | JPY 2,650,000–2,850,000 | JPY 3,300,000–3,600,000 |
| Enrollment | 695 | 470 |
| Boarding | Day only | Day only |
| Accreditations | CIS, NEASC, JCIS | CIS, NEASC |
Strengths
- ✓Full IB continuum (PYP + MYP + DP) under one roof — strong vertical academic coherence
- ✓Strong dual international accreditation: CIS + NEASC, plus JCIS membership
- ✓Long-established (since 1962) with a clear, distinctive Catholic, girls'-school identity
- ✓Documented EAL support plus dedicated learning-support specialists
- ✓Small class sizes (average ~20) and a low reported student-faculty ratio
- ✓Dual international accreditation (CIS since 2004 + NEASC) — strong governance and quality assurance
- ✓Authorized IB continuum across primary and middle years (PYP since 2005, MYP since 2007)
- ✓Genuinely small scale (~470 students, max class size 22) supporting individualized attention
- ✓Well-documented EAL programme — strong fit for families whose children are still developing English
- ✓Highly international community (70+ nationalities) and a tech-forward identity (Apple Distinguished School)
Trade-offs
- !IB Diploma results / average scores are not published — academic outcomes cannot be independently verified
- !Tuition is not published on the official site; fee data is third-party (school-reported) only
- !Single-sex from Grade 1 onward excludes boys beyond kindergarten
- !Catholic sponsorship may not suit families seeking a fully secular environment
- !No boarding — day-school only
- !DP is only at candidate stage, not authorized — TIS cannot yet be relied upon as a full IB Diploma school
- !The upper school is brand new (Grade 11 only since 2025) — no published graduation/placement track record exists
- !No public academic results — no IB scores or university-destination data
- !Official materials contain internal inconsistencies on grade range (K-8 vs K-11 vs K-12)
- !Premium fees with a recent sharp increase, against an as-yet-unproven senior school
Best Fit For
- • Families seeking a single-sex environment for girls within a rigorous IB pathway
- • Families who value a faith-rooted (Catholic) ethos with cultural/religious inclusivity
- • Younger families wanting a co-ed start in kindergarten that transitions to girls-only
- • Students needing EAL support entering an English-medium IB programme
- • Families with primary or middle-school-age children seeking an established, accredited IB PYP/MYP programme
- • Internationally mobile or non-native-English families needing strong EAL support
- • Families wanting a small, tech-integrated school in central Tokyo
University Placement
School-reported · not independently verified
School-reported, unverified: Seisen reports that 98% of graduates proceed to a higher educational institution. No specific university-destination lists or IB score averages are published.
Not public. As the upper school (G11/G12) and DP are newly established, no graduating-cohort outcomes exist yet.
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Frequently Asked Questions
Should I choose Seisen International School or Tokyo International School?
Seisen International School is best for: Families seeking a single-sex environment for girls within a rigorous IB pathway. Tokyo International School is best for: Families with primary or middle-school-age children seeking an established, accredited IB PYP/MYP programme. The right choice depends on target curriculum, budget, and family priorities — the two are not linearly comparable.
How do fees compare between Seisen International School and Tokyo International School?
Seisen International School: JPY 2,650,000–2,850,000. Tokyo International School: JPY 3,300,000–3,600,000. Verify against each school's own published fees; some figures are sourced from third-party aggregators.
What curricula do Seisen International School and Tokyo International School offer?
Seisen International School: IB. Tokyo International School: IB.
Do Seisen International School or Tokyo International School offer boarding?
Seisen International School: day school only. Tokyo International School: day school only.
This comparison is BrightKey's independent assessment using verifiable public data only. University-placement figures are school-reported and not independently verified. BrightKey takes no payments from schools. Our method →