Japanese people are serious about their holidays and typically take golden week, which is a full week off in May.

https://en.m.wikipedia.org/wiki/Golden_Week_(Japan)

A few years before the pandemic I visited Japan during Golden week, and Tokyo was basically empty. There were no cars on the street, there was no traffic, and the trains were only half full. Businesses were just closed, and I visited the financial district among other places; however Akihabara and other tourist districts were still very busy.

Japanese have a total of 16 official national holidays vs the US 11. However, people actually take them off, since many companies just close down entirely for those holidays, unlike say President's Day or Juneteenth in the US where everyone but banks and schools are still open.

And all of this is on top of their actual vacation time.

This website better explains it:

https://www.tokhimo.com/post/how-annual-leave-in-japan-work?lang=en