The calculated distance (air line) between Honchō and Minami-Sōma is approximately 144 miles respectively 232 kilometers.
By car or train, the actual journey to Minami-Sōma is certainly longer, as only the direct route (as the crow flies) between Honchō and Minami-Sōma has been calculated here.
Air line (approximately)
232 kilometers
125 nautical miles