Japnese are like Chinese, are quite obedient, therefore can follow quite throughly of the checks in the entry and exit of the country. Plus, itself has much more modern and disciplined public health system, with more experiences dealing with similar issues. Last but not least, the Japan lands are literally isolated from continents, making the transition of virus through other medium much more easier to track.
> Japnese are like Chinese I would advise you to never say to a Chinese or a Japanese that they are alike. Excepted if you want to enrich your vocabulary with new insults in a foreign language. Many of them are nationalists, and not really appreciating each other.
The countries which are winning against COVID are those who don't give loudspeakers to stupid people.
Just saying.