The PPP figure is irrelevant in this case. Purchasing Power Parity GDP figures adjusts the GDP to the cost of living. It has most contextual value when comparing the GDP per capita. PPP GDP per Capita is effectively a metric of the mean wealth relative to cost of living in the country.
To compare total GDP figures on a PPP basis for two countries, and when one country has 10x as many people doesn't really make sense.
What this comparison says is:
(Total GDP of Japan/Cost of Living in Japan) < (Total GDP of India/Cost of Living in India).
The Japanese economy is still 3x bigger (in terms of total GDP), and has 10x higher PPP GDP per capita, or about 30x the GDP per capita.
To compare total GDP figures on a PPP basis for two countries, and when one country has 10x as many people doesn't really make sense.
What this comparison says is:
(Total GDP of Japan/Cost of Living in Japan) < (Total GDP of India/Cost of Living in India).
The Japanese economy is still 3x bigger (in terms of total GDP), and has 10x higher PPP GDP per capita, or about 30x the GDP per capita.