As North Korea ratchets up international tensions with missile tests and aggressive rhetoric, some residents of a neighboring country are reportedly taking actions to protect themselves in advance.

As North Korea ratchets up international tensions with missile tests and aggressive rhetoric, some residents of a neighboring country are reportedly taking actions to protect themselves in advance. 
Reuters is reporting that “sales of nuclear shelters and radiation-blocking air purifiers have surged in Japan in recent weeks…” 
One company, Oribe Seiki Seisakusho, appears to be doing particularly well, receiving eight orders for nuclear shelters in April and selling all 50 of its $5,000-a-piece, poison gas filtering air purifiers.
According to Newsweek, the buying activity may have been prompted, at least in part, by Prime Minister Shinzo Abe’s recent warning to other Japanese government officials that “there is a possibility that North Korea already has a capability to put sarin on warheads to strike the ground.”
Meanwhile, the Japan Times reported last month that Oga, a Japanese city in Akita Prefecture, conducted the country’s first evacuation drill "on the premise of a ballistic missile falling into Japanese waters off Akita, [and] was aimed at promptly relaying information while facilitating the swift and safe evacuation of residents." The media outlet further notes that the drill included participation by an elementary school, among others.
In addition to these protective measures, Japan has been working with the U.S. and its neighbor South Korea to detect and possibly intercept approaching missiles.