# Yonshakudama (DD-680)

> Yonshakudama means '4-shaku shell'. A shaku is an old Japanese unit of about 30 cm, so the shell is about 120 cm across. It's the showpiece of the Katakai Fireworks Festival in Ojiya, Niigata, held on September 9-10 each year as an offering to Asahara Shrine. According to the festival, the shell weighs about 420 kg, climbs to about 800 m and bursts into a sphere about 800 m wide. Katakai first launched one successfully on September 10, 1985, and Guinness recognized it as the largest aerial firework shell at 418 kg. That record has since passed to a 4-shaku shell launched at the Kounosu festival in Saitama on October 11, 2014. It weighed 464.826 kg, reached 907 m at the top of its burst and spread 748 m wide.

- Department: Tech (also Locations)
- First published: 2025-12-17
- Last updated: 2025-12-17
- Permalink: https://detailenjoyer.com/case/yonshakudama/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## On the timeline

- **Sept. 10, 1985**: Katakai successfully launches its first 4-shaku shell, recognized by Guinness
- **Oct. 11, 2014**: A 464.826 kg shell at Kounosu, Saitama, sets the Guinness record

Full timeline: https://detailenjoyer.com/timeline/?case=yonshakudama

## Quick facts

- **DD-680-F01**: Katakai's yonshakudama weighs about 420 kg. _(Write-up · Exhibit A (The name))_
- **DD-680-F02**: The Guinness record shell (2014, Kounosu) weighed 464.826 kg. _(Write-up · Exhibit E (Record broken))_

## Write-up

A 420 kg firework shell. Katakai's 4-shaku shell blooms about 800 m wide.

1. **The name**: Shaku is an old Japanese length unit of about 30 cm. A 'yonshakudama' (4-shaku ball) is about 120 cm across, and Katakai is also known as the birthplace of the smaller 3-shaku shell.
2. **The numbers**: Katakai's festival puts its 4-shaku shell at 120 cm and about 420 kg, rising to about 800 m and blooming about 800 m wide.
3. **An offering**: The fireworks began as offerings to Asahara Shrine, sponsored by families and businesses to mark births, weddings or prayers for health. The festival is held on September 9-10 every year.
4. **Record history**: Katakai launched its first successful 4-shaku shell on September 10, 1985, and Guinness recognized the 418 kg shell as the largest aerial firework.
5. **Record broken**: On October 11, 2014, a 464.826 kg shell launched at Kounosu, Saitama, took the record, reaching 907 m to the top of its burst and blooming 748 m wide.

## Related case files

- [Winter in Harbin (DD-034)](https://detailenjoyer.com/case/winter-in-harbin/): Another big seasonal festival spectacle
- [Nuclear Fireball (DD-052)](https://detailenjoyer.com/case/nuclear-fireball/): Another giant burst in the sky
- [Gyotaku (DD-671)](https://detailenjoyer.com/case/gyotaku/): Another Japanese tradition

## Reel vs. record

- **Height understated**: Katakai says its 4-shaku shell climbs to about 800 m, well above 'more than half a kilometer'. The 2014 Kounosu record shell reached 907 m to the top of its burst.
- **Record holder**: Katakai's 1985 shell (418 kg) held the Guinness record, but a 464.826 kg shell launched at Kounosu, Saitama, in 2014 holds it now.
- **Weight detail**: Katakai gives about 420 kg (about 925 lb), so 'nearly 900 lbs' slightly undersells it.
- **Missing name**: 'yonshakudama' means '4-shaku shell'. A shaku is about 30 cm, which is where the 120 cm size comes from.
- **Missing context**: Katakai's fireworks are shrine offerings launched every September 9-10 in Ojiya, Niigata, and families or businesses sponsor individual shells.

## Video: Yonshakudama: A 420 kg Firework Shell

- Duration: 22.6 s · Published: 2025-12-17
- File: https://detailenjoyer.com/assets/videos/DSXGwIaESnV.mp4

### Transcript

DID YOU KNOW? The Yonshakudama firework is one of the largest aerial shells in the world, measuring about 1.2 m or 4 ft in diameter, and weighing over 400 kgs or nearly 900 lbs. This colossal shell is carefully hoisted into a reinforced mortar and blasted more than half a kilometer into the sky. When it detonates, it creates a gigantic sphere of light nearly 800 m or 2,600 ft wide. NOW YOU KNOW!

## Questions & answers

**Q: What does 'yonshakudama' mean?**  
A: A 4-shaku (about 120 cm) shell. _(Source: Write-up · Exhibit A (The name) · Travel to Tohoku (official tourism site): Katakai Festival; Katakai Festival: Introducing the 4-shaku shell (yonshakudama))_

**Q: About how much does Katakai's 4-shaku shell weigh?**  
A: About 420 kg. _(Source: Write-up · Exhibit B (The numbers) · Katakai Festival: Introducing the 4-shaku shell (yonshakudama); Discover Niigata: Katakai Fireworks Festival at Asahara Shrine)_

**Q: In which prefecture is the Katakai festival held?**  
A: Ojiya, Niigata. _(Source: Write-up · Exhibit C (An offering) · Travel to Tohoku (official tourism site): Katakai Festival)_

**Q: In what year did Katakai first launch a 4-shaku shell successfully?**  
A: September 10, 1985. _(Source: Write-up · Exhibit D (Record history) · Katakai Festival: Introducing the 4-shaku shell (yonshakudama); Guinness World Records (2016): Classics: Largest aerial firework shell)_

**Q: Where was the current Guinness record shell launched?**  
A: Kounosu, Saitama, in 2014. _(Source: Write-up · Exhibit E (Record broken) · Guinness World Records (2016): Classics: Largest aerial firework shell)_

## Sources

- [Katakai Festival: Introducing the 4-shaku shell (yonshakudama)](http://www.katakai.org/matsuri/yonsyaku_e.htm)
- [Guinness World Records (2016): Classics: Largest aerial firework shell](https://guinnessworldrecords.com/news/2016/1/classics-largest-aerial-firework-shell-411321)
- [Travel to Tohoku (official tourism site): Katakai Festival](https://www.tohokukanko.jp/en/attractions/detail_10071.html)
- [Discover Niigata: Katakai Fireworks Festival at Asahara Shrine](https://discover-niigata.com/travel-guide/13687/)

## Cite this case file

Easterling, Marcus. "Yonshakudama." The Detail Department (DetailEnjoyer), case file DD-680, last updated Dec 17, 2025. https://detailenjoyer.com/case/yonshakudama/