The calculated distance (air line) between Shirahamachō-usazakiminami and Okayama is approximately 45 miles respectively 73 kilometers.
By car or train, the actual journey to Okayama is certainly longer, as only the direct route (as the crow flies) between Shirahamachō-usazakiminami and Okayama has been calculated here.
Air line (approximately)
73 kilometers
39 nautical miles