Seisen International School

About the school

Seisen International School is a private Catholic day school for girls in Setagaya, Tokyo, run in the tradition of the Handmaids of the Sacred Heart of Jesus since 1962. It offers the IB PYP, MYP and Diploma Programme to about 700 students of over 40 nationalities, with a co-educational Montessori kindergarten.

Key facts

Founded

1962

IB Diploma since

1986

Students

about 700 (2026)

Nationalities

40+

Ages

2-18

Status

Private

Teaching languages

English, Japanese

Students

Girls

Boarding

No, day school

Programmes

• PYP
  Primary Years Programmeages 3 to 12
• MYP
  Middle Years Programmeages 11 to 16
• DP
  Diploma Programmeages 16 to 19, authorised in 1986

Accreditations: CIS, NEASC

Tuition fees

JP¥1,500,000 – JP¥2,700,000 per year

Annual fees published by the school (2026-27), from the youngest to the oldest year group. Registration, transport and meals may be extra. Source