Is $100 a day enough for Japan?

As someone interested in finance and the cost of living, I have to ask, is $100 a day truly enough to sustain oneself in Japan? Japan is known for its high cost of living, especially in major cities like Tokyo, where rent, transportation, and dining expenses can be steep. While $100 a day may be manageable in some smaller towns or rural areas, it's likely to be a stretch in the big cities. So, I'm curious, does this budget factor in the cost of housing, transportation, and other essential expenses? Or is it simply meant to cover daily discretionary spending?