The calculated distance (air line) between Yamazakichō-nakabirose and Okayama is approximately 43 miles respectively 68 kilometers.
By car or train, the actual journey to Okayama is certainly longer, as only the direct route (as the crow flies) between Yamazakichō-nakabirose and Okayama has been calculated here.
Air line (approximately)
68 kilometers
37 nautical miles