The British School in Tokyo vs Seisen International School
🇯🇵 Tokyo · Side-by-side comparison on verifiable public data.
Neither The British School in Tokyo nor Seisen 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 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
| The British School in Tokyo | Seisen International School | |
|---|---|---|
| Curriculum | British / IB | IB |
| Ages | 3–18 | 2–18 |
| Languages of instruction | English | English |
| Annual fees | JPY 2,960,000–3,070,000 | JPY 2,650,000–2,850,000 |
| Enrollment | 1,400 | 695 |
| Boarding | Day only | Day only |
| Accreditations | CIS, NEASC, JCIS |
Strengths
- ✓Long pedigree (since 1989) and scale — ~1,400 students, 60–65 nationalities, the largest British school in Japan
- ✓Strong, publicly-published exam results (2025 A-Level 59% A*/A; IGCSE 68% A*/A)
- ✓Credible, transparent university-destination list including UCL, Imperial, Cambridge, LSE
- ✓All-native-English-speaker faculty with UK qualifications
- ✓Modern facilities — new Azabudai Hills primary campus (2023) and refurbished secondary (2025)
- ✓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
Trade-offs
- !No public BSO or ISI inspection rating found — no external inspection band to verify quality, unlike British peers such as Tanglin
- !Accreditation is unclear: COBIS participation is evident, but accredited-membership/BSO status is not confirmed on any public directory
- !Sixth form is mid-transition (A-Levels phasing out by 2026, IB DP ramping up) — no IB results track record yet
- !No EAL support — unsuitable for families whose children aren't already fluent in English
- !Premium fees with annual increases plus sizeable one-time enrolment and resources fees
- !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
Best Fit For
- • Anglophone expatriate families wanting a continuous British-curriculum pathway
- • Already-fluent English-speaking children (native or near-native)
- • Families targeting UK/competitive global university admission who value a published results record
- • 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
University Placement
School-reported · not independently verified
School-reported, unverified: 2024–25 destinations include UCL (x10), Imperial (x3), Cambridge, LSE, Bath, plus Waseda, Sophia, Toronto, McGill and Williams College.
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.
More Comparisons
Frequently Asked Questions
Should I choose The British School in Tokyo or Seisen International School?
The British School in Tokyo is best for: Anglophone expatriate families wanting a continuous British-curriculum pathway. Seisen International School is best for: Families seeking a single-sex environment for girls within a rigorous IB pathway. The right choice depends on target curriculum, budget, and family priorities — the two are not linearly comparable.
How do fees compare between The British School in Tokyo and Seisen International School?
The British School in Tokyo: JPY 2,960,000–3,070,000. Seisen International School: JPY 2,650,000–2,850,000. Verify against each school's own published fees; some figures are sourced from third-party aggregators.
What curricula do The British School in Tokyo and Seisen International School offer?
The British School in Tokyo: British, IB. Seisen International School: IB.
Do The British School in Tokyo or Seisen International School offer boarding?
The British School in Tokyo: day school only. Seisen 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 →