based on my several years living in Japan:

- cleanliness is a big part of their culture
- they bow rather than shake hands
- they rarely hold hands, hug, or kiss in public; in fact, physical contact of any kind is rare in public, even among spouses
- many Japanese wear face masks any time they feel even the slightest bit ill, and were doing this long before anyone had heard of COVID-19
- they have a very healthy diet and you rarely see obese people there
- very few Japanese women smoke (although men do)
- they are an island nation, sharing no land borders with anyone; you basically have to fly to get there

They did take other actions besides closing schools and universities early on. They also postponed the start of baseball season and banned events with large crowds. They also quarantined international visitors. (When I lived there, every time I entered the country I had to let them know if I had had a cold or runny nose or respiratory illness recently — this was in the early 2000s.)