A television screen showing reports of a North Korean missile launch, May 2024.
The Japanese government is moving to designate additional underground shelters in preparation for a potential missile attack, according to interviews with the Cabinet Secretariat and other sources on March 9. The goal is to expand underground shelter capacity to cover just under 10% of the population — roughly 10 million people in total, including facilities already designated.
Prime Minister Sanae Takaichi has called Japan's current security environment "the most severe and complex" since the end of World War II, underscoring the urgency of securing adequate shelter.
The issue has taken on fresh relevance following United States–Israeli strikes on Iran that began on February 28, during which cities came under missile attack and civilians reportedly sheltered underground.
Designation of Shelters
Under Japan's Civil Protection Law, prefectures and government-designated cities are responsible for selecting emergency evacuation facilities. People should be able to take refuge in these locations for one to two hours during a missile strike or similar emergency. These shelters can be located both above and below ground.
Underground shelters include facilities such as subway stations and underground parking lots. As of April 2025, there were 4,233 designated underground sites. Including sturdy above-ground buildings, the total number of designated shelters reached 61,142.
A Cabinet Secretariat survey from fiscal 2024 identified 1,489 undesignated underground facilities nationwide that could potentially serve as shelters, with a combined floor area of approximately 4 million square meters (about 43 million sq ft).
Size Requirements
Under national standards, each evacuee requires 0.825 square meters (about 8.9 sq ft) of floor space. Adding these facilities to existing shelters would bring the total underground floor area to about 8.91 million square meters (roughly 96 million sq ft) — enough to accommodate approximately 10.8 million people.
With Japan's population at approximately 122.95 million as of January 2026, that capacity would cover about 8.7% of the population, up from 5.5% in April 2025. The Cabinet Secretariat said it "would like to designate them as shelters if possible."
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(Read the article in Japanese.)
Author: The Sankei Shimbun
