The calculated distance (air line) between Okayama and Higashi-ōsaka is approximately 94 miles respectively 151 kilometers.
By car or train, the actual journey to Higashi-ōsaka is certainly longer, as only the direct route (as the crow flies) between Okayama and Higashi-ōsaka has been calculated here.
Air line (approximately)
151 kilometers
81 nautical miles