Your question is too broad, but to give at least one data point: a data science dev with a few years of experience (1 to 5), can expect between ¥6M and ¥12M/yea

Your question is too broad, but to give at least one data point: a data science dev with a few years of experience (1 to 5), can expect between ¥6M and ¥12M/year in a startup. > it should at least be higher than megacorps Yes, with exceptions > how much culture clash there are for foreigners In my subjective and limited experience, not much. Start-ups in Japan are rare (compared to most tech cities), Japanese founders/employees often do not want to emulate the working culture of big companies, on the contrary they might work in a startup to avoid it. Knowledge of English and living abroad experience also seem more common than average