How many hours a day do you spend in average in the office? How much flexible are your hours?
Which technologies do you use and what's your salary range?
Although for USA and EU the internet is full of information, it's hard to find actual data for Japan. I'm thinking in particular to startups.
You'll find wide variability with regards to working hours in startups, with most of the range covering "high-growth US startup" or "Japanese professional employment" levels of expectations rather than "unionized public sector worker in US or Europe" level of expectations. You will find similar variance in flexibility.