[1/7] Megumi Morohoshi, a Japanese mother of three, poses for a photo inside her family's newly installed bomb shelter in Saitama, Japan December 5, 2022.
But the invasion of Ukraine followed by a barrage of North Korean missiles convinced her the threat was urgent.
And the following month an intercontinental ballistic missile (ICBM) landed just 200 km (130 miles) from the northwestern coast.
The shelters, custom-built at Nao's factory in Ibaraki prefecture, north of Tokyo, cost 6 million yen ($44,000) before installation expenses.
Morohoshi's unit, delivered late last month, is an austere white box with "CRISIS-01" emblazoned on the side, with external cameras mounted on it.