* Definition of "family": This can vary – nuclear family, extended family, etc. Statistics often use different definitions.
* Income measure: Is it gross income, net income (after taxes), or disposable income (after taxes and other deductions)?
* Geographic location: Income varies significantly between Tokyo (much higher) and rural areas.
* Household size: Larger households may have higher total income but lower per capita income.
* Year: Income levels change year to year due to economic fluctuations.
While precise figures require specifying the above parameters and consulting recent Japanese government statistics (like those from the Statistics Bureau of Japan), you can find data on average household income in various reports. These reports often show the average *household* income, not necessarily the average *family* income (though the terms are sometimes used interchangeably).
To find the most up-to-date and specific information, you should search for official statistics from the Japanese government or reputable news sources covering Japanese economic data. Look for keywords like "average household income Japan," "Japanese household income statistics," or "Japanese family income data." Be sure to pay close attention to the methodology used in the data you find.