The calculated distance (air line) between Hiroshima and Imarichō-kō is approximately 167 miles respectively 268 kilometers.
By car or train, the actual journey to Imarichō-kō is certainly longer, as only the direct route (as the crow flies) between Hiroshima and Imarichō-kō has been calculated here.
Air line (approximately)
268 kilometers
145 nautical miles