This question is also answered by the MHLW statistics [1].
On page 2, the line graph at the top represents the percentage of available paid leave days taken on average, with the absolute numbers below. So, the average worker in Heisei 25 (2013) had 18.5 days of leave, of which he took 9.0, or 48.8%.
(Not including public holidays.)
[1] https://www.mhlw.go.jp/file/05-Shingikai-11201000-Roudoukiju... (in Japanese)
I’m not saying they don’t, but legally Japanese workers have more paid time off than Americans [1]. Japan also has a larger number of public holidays, which while not legally enforced, are generally taken.
I’d be curious to see data about when people actually arrive at and leave work, and how many holidays are taken.
[1] 10+ days versus 0. https://en.m.wikipedia.org/wiki/List_of_minimum_annual_leave...