The calculated distance (air line) between Higashi-ōsaka and Gamagōri is approximately 94 miles respectively 152 kilometers.
By car or train, the actual journey to Gamagōri is certainly longer, as only the direct route (as the crow flies) between Higashi-ōsaka and Gamagōri has been calculated here.
Air line (approximately)
152 kilometers
82 nautical miles