The calculated distance (air line) between Ōnojō and Nishifukuma is approximately 16 miles respectively 26 kilometers.
By car or train, the actual journey to Nishifukuma is certainly longer, as only the direct route (as the crow flies) between Ōnojō and Nishifukuma has been calculated here.
Air line (approximately)
26 kilometers
14 nautical miles