Japan is about 3.2 times smaller than South Africa.

South Africa is approximately 1,219,090 sq km, while Japan is approximately 377,915 sq km, making Japan 31.0% the size of South Africa. Meanwhile, the population of South Africa is ~57.5 million people (66.7 million more people live in Japan).
Tip: This to-scale comparison of South Africa vs. Japan uses the Mercator projection, which distorts the size of regions near the poles.
Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.