The calculated distance (air line) between Higashi-ōsaka and Ōmihachiman is approximately 43 miles respectively 70 kilometers.
By car or train, the actual journey to Ōmihachiman is certainly longer, as only the direct route (as the crow flies) between Higashi-ōsaka and Ōmihachiman has been calculated here.
Air line (approximately)
70 kilometers
38 nautical miles