Coming of Age Day in Japan: Honoring New Adults with Tradition and Celebration

Imagine a day when an entire country pauses to celebrate its youth—marking their first steps into adulthood with elegance, tradition, and heartfelt pride.

In Japan, Coming of Age Day—known as Seijin no Hi (成人の日)—is more than just a national holiday. Celebrated on the second Monday of January, it’s a powerful rite of passage that honors those reaching a symbolic age of maturity.

Traditionally, the day marks the transition into adulthood at 20 years old—a milestone deeply rooted in Japanese culture. However, since 2022, when Japan officially lowered the legal age of adulthood to 18, the significance of this holiday has begun to evolve. Despite the legal change, most Coming of Age Ceremonies continue to celebrate those turning 20, preserving the customs and cultural meaning passed down through generations.

In this article, we explore the meaning, customs, and changing landscape of one of Japan’s most symbolic celebrations.

Historical Roots: Coming of Age in Traditional Japan

Long before Seijin no Hi became a modern national holiday, Japanese society observed its own coming-of-age rituals—rooted in the imperial court and samurai traditions.

Genpuku (元服): For Boys

Originating in the Nara period (710–794) and continuing through the Heian, Kamakura, and Edo periods, genpuku was a ceremonial rite marking a boy’s transition into adulthood, usually between ages 12 and 16, depending on social class.

Boys changed into adult-style clothing appropriate for their status.
They often adopted a new adult name, leaving behind their childhood name (yōmyō).
In aristocratic and warrior families, they would wear a formal court cap (eboshi) and sometimes receive a ceremonial crown (kanmuri).
The hairstyle was also changed to an adult form. In later periods, especially during the Edo era, the practice evolved—samurai and commoners often shaved their forelocks (maegami) and performed the sakayaki style, while nobility retained more elaborate traditions.

The ceremony was also known as kakan (加冠) or uikōburi (初冠), referring to the placing of a crown or cap as a symbol of entering adult society.

Mogi (裳着): For Girls

For noble girls, especially in the imperial court, the counterpart to genpuku was mogi, a formal ceremony that marked a girl's transition from childhood to womanhood.

The ceremony involved dressing the girl for the first time in a formal layered kimono, including the symbolic mo (裳)—a long trailing skirt worn around the waist.
It was typically held between the ages of 12 and 16, often at a significant life stage such as engagement or impending marriage.
Alongside the dressing ritual, the girl's hair was styled in an adult fashion—a practice known as kami-age (髪上げ), which symbolized her transformation into a woman.
Like genpuku, mogi was a public and prestigious event in aristocratic circles, symbolizing family honor and readiness for adult social roles.

While mogi was less widespread than genpuku, it held deep cultural and symbolic value—especially among court nobility—connecting ideals of beauty, family status, and societal expectations of women.

Though these traditions eventually faded with modernization, they laid the cultural foundation for what would later become Seijin no Hi—a formal celebration of maturity, identity, and social belonging that still resonates in Japan today.

The Modern Establishment of Coming of Age Day

While Seijin no Hi as a holiday was officially created in the late 1940s, the custom of holding a formal coming-of-age ceremony in modern Japan began earlier.

Japan's First Modern Seijin Shiki

The first Coming of Age Ceremony (Seijin Shiki) was held on November 22, 1946, in the town of Warabi (now Warabi City) in Saitama Prefecture. The event was called the "Youth Festival" (青年祭) and was created to inspire and encourage young people during the harsh years of postwar recovery.

Even in the face of poverty and national hardship following World War II, local leaders in Warabi hoped to give the next generation a sense of hope, pride, and responsibility. This event is widely recognized as the prototype for the modern Seijin Shiki, and it strongly influenced national policymakers.

Official Establishment of the Holiday

In 1948, just two years after Warabi’s Youth Festival, the Japanese government designated January 15 as a new national holiday: Coming of Age Day (Seijin no Hi).
The holiday aimed to encourage young adults to take pride in their role as future leaders of society and to mark their growth into adulthood with a sense of purpose.

Why January 15?

Although the original Youth Festival in Warabi was held in November, the government chose January 15 for a symbolic reason:
In ancient Japan, coming-of-age rituals like genpuku were often held in January, especially around the New Year. This was because of the traditional use of kazoedoshi (数え年)—an age system where people gained one year at the start of each new year. Holding genpuku in January was a way to honor this symbolic moment of new growth.

Thus, January 15 was selected to reflect both cultural tradition and the spirit of renewal.

Change Under the “Happy Monday” System

In 2000, as part of a nationwide reform to encourage work-life balance, Seijin no Hi was moved to the second Monday of January to create a three-day weekend. Despite the date shift, the meaning of the holiday remains unchanged: a celebration of growth, maturity, and hope for the future.

What Happens on Coming of Age Day?

Coming of Age Day continues to thrive as a meaningful tradition in modern Japan. So how do people celebrate this important milestone today?

The Seijin Shiki (Coming of Age Ceremony)

The centerpiece of Coming of Age Day is the Seijin Shiki, or Coming of Age Ceremony, held at public venues like community centers and city halls across the country. Local governments invite young people who have turned or will turn 20 years old during the current school year.

Key Features of Seijin Shiki:

Women wear elegant furisode—a long-sleeved kimono reserved for unmarried women.
Men typically wear suits, though some opt for traditional hakama or montsuki-style outfits.
Ceremonies include congratulatory speeches from local officials and community leaders.
Attendees often reunite with childhood friends and take keepsake photos.
Many celebrate with family and friends after the formal event.

This ceremony is a meaningful rite of passage and becomes a cherished memory for many.

Why Is Coming of Age Day Important?

More than a festive occasion, Seijin no Hi serves as a powerful societal and personal milestone in Japan.

A Symbol of Social Responsibility

Turning 20 in Japan traditionally marks the moment when individuals are considered full-fledged members of society. They gain the legal right to:

the ability to sign contracts independently without parental consent (from age 18)
the right to vote in elections (also from age 18)
the legal right to consume alcohol and tobacco, and to participate in certain forms of gambling (from age 20)
being considered fully responsible under the law as adults

Note: While the legal age of adulthood in Japan was lowered to 18 in 2022—granting rights such as voting and independent contract signing—the age for drinking, smoking, and other adult privileges remains 20.

The day symbolizes not only new freedoms, but also new responsibilities—to contribute to society, act with maturity, and begin shaping one’s own future.

A Personal Rite of Passage

For many young people, Seijin no Hi is the first time they publicly reflect on their journey from childhood to adulthood.
It offers a moment to acknowledge the efforts of parents, teachers, and mentors, and to express gratitude before stepping into the next stage of life. The day is often filled with mixed emotions—joy, nostalgia, pride, and anticipation.

A Cultural Expression of Continuity

Coming of Age Day is also important on a cultural level. In a rapidly changing modern world, it preserves a sense of ritual and identity.
By gathering young adults in a shared ceremony, society reaffirms its trust in the next generation and the values that connect past, present, and future.

Even as family structures, gender roles, and career paths evolve, Seijin no Hi remains a timeless tradition that emphasizes growth, responsibility, and belonging.

In this way, the importance of Coming of Age Day lies not only in celebrating the individual, but in reinforcing the collective hopes and ideals of an entire nation.

Legal Changes and Cultural Continuity

In April 2022, Japan officially lowered the legal age of adulthood from 20 to 18. This change granted 18-year-olds new rights—such as signing contracts, applying for credit cards, and living independently without parental approval.

However, despite the legal revision, most municipalities across Japan have continued to hold Coming of Age ceremonies for those turning 20, often rebranding the event as a “20-Year-Old Gathering” (二十歳のつどい) rather than Seijin Shiki in the strict legal sense. Why is 20 still the focus?

Practical Considerations

Most 18-year-olds are still in high school, often in their final year and deeply involved in exams, club activities, or preparing for university or employment. Holding a major ceremony during this period is neither practical nor inclusive.
Many 18-year-olds are still transitioning into adulthood and may not yet feel socially or emotionally prepared for such a rite of passage.
At 20, individuals are often more settled—living independently or starting careers—and can fully appreciate the meaning of the ceremony.

Social and Cultural Preference

Municipalities, schools, and families overwhelmingly prefer to mark the occasion at age 20, when young adults have more autonomy and availability.
The event also coincides with other legal milestones, such as the right to drink, smoke, and gamble, further reinforcing its symbolic importance.

In this way, the persistence of celebrating at age 20 is not only cultural—but also practical. It reflects a balance between legal policy and the lived realities of young people in Japan.

Modern Trends and Social Changes

As with many long-standing traditions, Seijin no Hi is evolving to reflect the realities of modern Japanese society.

Japan’s declining birthrate has led to fewer participants in some regions, particularly rural areas.
During the COVID-19 pandemic, many municipalities implemented virtual ceremonies, postponed events, or held smaller, decentralized gatherings to prioritize safety.
Some local governments have begun exploring more inclusive formats, seeking to accommodate diverse participants, such as foreign residents or those who may not conform to traditional gender norms.
There have also been a few experimental cases of celebrating both 18- and 20-year-olds, though the vast majority continue to focus on 20.

These gradual adaptations reflect a broader effort to ensure that Seijin Shiki remains relevant, respectful, and accessible—preserving the tradition while acknowledging the diversity of young adults in today’s Japan.

The Spirit of Seijin no Hi

Coming of Age Day in Japan is far more than a ceremonial event—it is a reflection of the nation's values, its connection to tradition, and its hopes for the future.

Across generations, Seijin no Hi has honored the moment when individuals step out of childhood and into society, embracing not only new rights but also deeper responsibilities. Even as laws evolve and lifestyles diversify, the core spirit of this day endures: to celebrate growth, acknowledge legacy, and empower the next generation.

By bringing families, communities, and young adults together, Seijin no Hi reaffirms a shared belief—that the strength of society lies not only in its past, but in the promise of those just beginning their journey. It is a day of pride, purpose, and passage—and one that continues to shape Japan’s cultural heart.