The calculated distance (air line) between Kitakyushu and Bungo-Takada-shi is approximately 40 miles respectively 64 kilometers.
By car or train, the actual journey to Bungo-Takada-shi is certainly longer, as only the direct route (as the crow flies) between Kitakyushu and Bungo-Takada-shi has been calculated here.
Air line (approximately)
64 kilometers
35 nautical miles