The calculated distance (air line) between Ōmamachō-ōmama and Chiba is approximately 74 miles respectively 120 kilometers.
By car or train, the actual journey to Chiba is certainly longer, as only the direct route (as the crow flies) between Ōmamachō-ōmama and Chiba has been calculated here.
Air line (approximately)
120 kilometers
64 nautical miles