Ninja Day in Japan

PUBLISHED 22 FEB 2026

Tourism, Tradition and the Relentless Spirit of the Ninja

February 22nd is “Ninja Day” in Japan—a playful linguistic nod to the pronunciation of the number two. In Japanese, 2-2-2 can be read ni-ni-ni, echoing the familiar “nin-nin” associated with ninja folklore. What began as wordplay has evolved into an annual celebration of Japan’s shinobi heritage, particularly in the regions most closely tied to the historical ninja families.

The city of Koka in Shiga Prefecture—long regarded as a birthplace of the Kōka ninja tradition—has embraced the date as a way of promoting local identity and tourism. Municipal employees have previously donned ninja attire to mark the occasion, blending civic pride with cultural history.

Meanwhile, Iga, synonymous with the Iga-ryū lineage, has gone even further in celebrating its shinobi roots. According to Japan’s Mainichi newspaper:

Ahead of ‘Ninja Day’, the municipal headquarters morphed into Ninja City Hall with staff at the first-floor service counters attending to visitors in ninja costumes.

At the opening ceremony, Mayor Toshinao Inamori, dressed as a shinobi, declared, ‘We will protect the important regional resource of ninja and connect it to the future.’

Officials unveiled both a navy blue banner, measuring 1.3 meters wide and 2.4 m long, with the message ‘Welcome to Ninja City’.

Festive as it may seem, Ninja Day is more than costume and spectacle. In 2026, the celebration carries particular weight: it marks 350 years since the compilation of the Bansenshukai, the most comprehensive surviving manual of classical ninjutsu.

350 Years of the Bansenshukai

Compiled in 1676, the Bansenshukai stands as one of the definitive texts on shinobi strategy, espionage, philosophy, and fieldcraft. Its ten volumes—spanning approximately 1,000 pages—offer rare insight into the mindset and methods of the historical ninja.

To honour this milestone, a group of dedicated ninja enthusiasts in Koka are undertaking an extraordinary challenge: a 60-Hour Endurance Manuscript Project. Gathering inside a traditional Japanese house, they aim to hand-copy all ten volumes of the Bansenshukai—every page, every character—without sleep or rest.

This is no quiet scholarly exercise. It is being broadcast live on YouTube by Nin Tube as a special Ninja Day endurance livestream.

A Livestream with Consequences

The project is carefully timed. Each character is to be transcribed with precision, with the goal of completing the manuscript at exactly 10:22 p.m. on February 22nd—Ninja Day itself.

But there is an additional twist.

Viewer engagement directly affects the challengers’ comfort and survival conditions. Their “food, clothing, and shelter” depend on the level of audience support and the successful completion of live challenges. Access to meals, toilet breaks, bathing, and even sleep is conditional. At certain times, participants may be required to sit in seiza (formal kneeling posture) or work in complete silence.

In effect, the endurance test becomes a modern echo of shinobi discipline—mental resilience, physical discomfort, and unwavering focus under pressure.

February 22nd vs December 5th

It is worth noting that Japan’s February 22nd Ninja Day should not be confused with International Ninja Day, celebrated annually on December 5th. Created in 2003 by Ninja Burger, the December event leans heavily into pop culture—encouraging costumes, stealth games, and ninja film marathons.

By contrast, February 22nd in Japan is rooted more firmly in regional heritage, particularly in Iga and Koka, where shinobi history is woven into local identity.