The calculated distance (air line) between Nambu and Higashi-ōsaka is approximately 168 miles respectively 270 kilometers.
By car or train, the actual journey to Higashi-ōsaka is certainly longer, as only the direct route (as the crow flies) between Nambu and Higashi-ōsaka has been calculated here.
Air line (approximately)
270 kilometers
146 nautical miles