Half an hour after North Korea launched a ballistic missile, albeit unsuccessfully, last Saturday, trains running 1,200km away in Tokyo's extensive underground metro network ground to a halt.
Flak from Japanese reluctant to let wayward North Korea disrupt everyday life came fast and furious.
Notwithstanding their protests, there has been a surge of interest in how to guard against ballistic missile and nuclear attacks.
Japan has drawn up detailed civil defence guidelines on its Cabinet Secretariat Civil Protection portal on what people should do in the event of an attack. The website's page views jumped exponentially from 450,000 in March to about three million last month.
Companies specialising in nuclear bunkers and air purifiers that can remove radioactive and chemical substances say they are receiving more inquiries about products.
LIVING WITH THE N. KOREAN THREAT
Tensions on the Korean peninsula have risen in recent weeks, with Pyongyang unleashing war threats against the United States and its allies. What is it like living within striking range of North Korea's artillery and missiles? Our correspondents in South Korea and Japan take stock of the mood in these two countries.
We can't possibly go into hiding or drastically change our way of life because of an attack that may never happen. That would, frankly, be just alarmist.
BUSINESSMAN YUTO TANAKA
The chief executive officer of Osaka-based Shelter Co, Mr Seichiro Nishimoto, 80, told the Nikkei Asian Review: "We sell only a few of these a year, but we surpassed our annual sales in a single month.
"I've been selling nuclear shelters for 55 years now and I'm overwhelmed by the flood of inquiries. I've never seen anything like this."
Earth Shift Co, a Shizuoka-based firm, now gets 20 to 50 calls a day for its underground shelters, up from just a few dozen in a year.
Japan, located on multiple fault lines and whose disaster response to devastating earthquakes in recent years has been found wanting, is taking no chances when it comes to North Korea.
On Wednesday, North Korean state media Rodong Sinmun warned that should war break out, Japan would be "put under radioactive clouds before any country".
Pyongyang had, in March, declared that a ballistic missile test had been a successful dry run for a strike on American bases in Japan.
Akita and Nagasaki prefectures, which are home to US bases, have responded by conducting evacuation drills for its residents.
Though the central government admitted that a warning can reasonably be issued, at most, 10 minutes before impact, it has issued instructions. Those outdoors should seek refuge in strong buildings or, better yet, go underground. Those indoors should stay low, take cover and keep away from glass windows.
Warnings will be disseminated across multiple platforms including outdoor loudspeakers, television, radio and mobile phones through the nationwide J-Alert system that is typically used to notify the public of earthquakes.Tokyo Metro says it will now halt services only if the J-Alert system is activated.
A Twitter user said: "Only Tokyo Metro stopped its trains, while most other railway lines continued running. Even the subway in Seoul had not stopped. What's with that?"
That sums up the general sentiment in Japan where, amid the sabre-rattling from Pyongyang, people are enjoying the annual Golden Week holidays this week.
The hip Omotesando district was packed with shoppers and cafe-goers on Wednesday. One of them, 32-year-old businessman Yuto Tanaka, said he was concerned but did not think Japan is on the verge of an attack. Not much could be done beyond knowing what to do if a missile strike were to occur, he added.
"We can't possibly go into hiding or drastically change our way of life because of an attack that may never happen," he said. "That would, frankly, be just alarmist."