The calculated distance (air line) between Ōmuta and Imarichō-kō is approximately 37 miles respectively 60 kilometers.
By car or train, the actual journey to Imarichō-kō is certainly longer, as only the direct route (as the crow flies) between Ōmuta and Imarichō-kō has been calculated here.
Air line (approximately)
60 kilometers
32 nautical miles