The calculated distance (air line) between Hamamatsu and Nishi-Tokyo-shi is approximately 124 miles respectively 200 kilometers.
By car or train, the actual journey to Nishi-Tokyo-shi is certainly longer, as only the direct route (as the crow flies) between Hamamatsu and Nishi-Tokyo-shi has been calculated here.
Air line (approximately)
200 kilometers
108 nautical miles