The calculated distance (air line) between Ōmuta and Maebaru-chūō is approximately 39 miles respectively 63 kilometers.
By car or train, the actual journey to Maebaru-chūō is certainly longer, as only the direct route (as the crow flies) between Ōmuta and Maebaru-chūō has been calculated here.
Air line (approximately)
63 kilometers
34 nautical miles