A health class in a lower-secondary school. The teacher opens the textbook page on “bodily changes in puberty” and explains hormones and secondary sex characteristics. The next page covers “fertilisation and pregnancy”, but the teacher says “we don’t cover this part” and skips the chapter. The students never learn what intercourse refers to, at home or at school, and turn to the internet instead. This was long the standard of Japanese schools, the reach of sex education bounded by the curriculum’s “brake clause”.

Sex education (性教育) is the systematic teaching of scientific knowledge, ethics, interpersonal relations, and human rights around sexuality. Japanese school sex education has developed amid several tensions: the framing of content by the curriculum guidelines, the debate over the “brake clause”, episodes of political intervention in the classroom, and the gap with UNESCO’s International Technical Guidance on Sexuality Education. This article covers the concept, the Japanese trajectory, the related cases, the international current, and the points of debate.

The concept

The reach of “sex education” varies by context. Narrowly it means school health-science teaching (secondary sex characteristics, fertilisation, pregnancy, STIs); broadly it adds sexual orientation, gender diversity, sexual consent, relationships, violence prevention, and media literacy, corresponding to the “comprehensive sexuality education” (CSE) concept advanced by UNESCO. The Japanese lower-secondary curriculum (health and physical education) long carried a note that “the course of pregnancy shall not be treated”, commonly called the “brake clause”, meaning that the teaching of the fertilisation process including intercourse is not covered at the lower-secondary stage. Introduced in the curriculum from 1998, it is maintained in the current 2017 version.

The Japanese trajectory

Postwar sex education began with the Ministry of Education’s 1947 “Basic Principles of Purity Education”, normative teaching centred on STI prevention and “purity”. The 1990s were a period of enrichment, with “human development” taught in fifth-grade science from 1992 and many books and teaching materials published, sometimes called the “first year of sex education”. From the 2000s, conservative legislators and groups mounted criticism; the 2002 lower-secondary curriculum introduced the “brake clause”, narrowing the reach, and the 2003 Nanao case became its symbol. From the 2010s the need for sex education was reassessed against teenage pregnancy, STIs, and sexual violence; the 2018 Adachi Ward case over a class on contraception and abortion, and from 2021 the “life-safety education” programme, marked renewed government and local engagement.

Related cases

The 2003 Nanao case concerned sex-education bashing at the Tokyo Metropolitan Nanao School for children with intellectual disabilities. The school had developed, from 1997, a “heart and body learning” curriculum teaching the names and functions of body parts through songs and dolls. In July 2003 three metropolitan-assembly members inspected the school, criticised the materials as “unthinkable” and “inappropriate”, and the metropolitan education board issued reprimands and seized the materials. Teachers and parents sued the assembly members and the metropolis; the Tokyo District Court (2009) and Tokyo High Court (2011) found for the plaintiffs, holding the members’ conduct an “unlawful political intervention infringing the autonomy of education”. The Supreme Court dismissed both sides’ appeals on 28 November 2013, finalising the judgment, a leading precedent on the limits of political intervention in sex education.

The 2018 Adachi Ward case concerned a lower-secondary class on contraception and abortion criticised by a metropolitan-assembly member as contrary to the curriculum; the metropolitan and ward education boards ultimately found the class “not necessarily in violation of the curriculum guidelines”, confirming room for sex education using independent materials.

The international current

UNESCO, with UNAIDS, UNFPA, UNICEF, WHO (and later UN Women), published the International Technical Guidance on Sexuality Education in 2009, revised in 2018. It defines sexuality education as a “curriculum-based process of teaching and learning about the cognitive, emotional, physical and social aspects of sexuality”, presenting content for ages 5–18 in four stages around eight key concepts (relationships; values, rights, culture and sexuality; gender; violence and safety; skills for health and well-being; the human body and development; sexuality and sexual behaviour; sexual and reproductive health). CSE teaches not only anatomical knowledge but human rights, gender equality, relationships, sexual consent, LGBTQ, and violence prevention.

The Netherlands, Sweden, and Finland are leading examples of CSE in the curriculum; the US varies sharply by state, with abstinence-only education in conservative states; England made Relationships Education and Relationships and Sex Education compulsory from 2020. International research reports that CSE lowers teenage-pregnancy and STI rates, while abstinence-only education does not curb adolescent sexual behaviour and, through a lack of contraceptive knowledge, raises the risk of unintended pregnancy and infection.

Points of debate

The lower-secondary “brake clause” has been criticised continuously by researchers and teachers; with the 2023 Penal Code raising the age of consent to 16, not treating intercourse in compulsory education sits in tension with that change. The Nanao case marks the limit of political intervention, but episodes continue, and the chilling effect on teachers is a continuing concern. Measured against the UNESCO guidance, Japanese school sex education weights anatomy and physiology heavily and relationships, consent, LGBTQ, and violence prevention lightly; MEXT’s 2021 “life-safety education” strengthens violence-prevention teaching, but institutional and practical gaps from the comprehensiveness of CSE remain. NPOs and advocacy groups (Pilcon, SHIP, Nijiiro Gakko) supplement the shortfall through guest lessons, materials, and teacher training, functioning as pressure for reform of public education.

See also

• Sexual consent
• LGBTQ
• Freedom of expression
• Zoning
• Sexual harassment