The calculated distance (air line) between Ōyama-kanaichō and Yokohama is approximately 22 miles respectively 35 kilometers.
By car or train, the actual journey to Yokohama is certainly longer, as only the direct route (as the crow flies) between Ōyama-kanaichō and Yokohama has been calculated here.
Air line (approximately)
35 kilometers
19 nautical miles