The calculated distance (air line) between Ōdachō-ōda and Hiroshima is approximately 55 miles respectively 88 kilometers.
By car or train, the actual journey to Hiroshima is certainly longer, as only the direct route (as the crow flies) between Ōdachō-ōda and Hiroshima has been calculated here.
Air line (approximately)
88 kilometers
48 nautical miles