Each yonshakudama shell made by Katakai Fireworks weighs 420kg or, “about the same as two sumo wrestlers,” says CEO Masanori Honda. During a fireworks festival held each September not far from the Niigata company, two of the 120cm diameter behemoths are blasted into the air to explode in 800m-wide balls of fire.
Honda’s company makes about 100,000 fireworks a year. Each sturdy concrete building in the compound – generously spaced out for safety – houses a different part of the manufacturing process. Yet, for such hazardous work, the plant is surprisingly serene, lovingly landscaped with flower beds and a water feature. In spring the cherry trees burst into spectacular bloom.
The CEO gestures towards an innocuous-looking tray of grey material. It is gunpowder-coated cork, laid out to dry in the sun. “Enough to kill 10 people if it went off,” he says matter-of-factly.
Then we move on to the factory’s most dangerous location – the chemical mixing room – where Honda politely asks me to switch off my high-voltage flash. It just might, he says, ignite airborne particles of explosive.
I don’t need to be told twice.