Two theories explain the events mentioned above: One says that Arimitsu changed his name to Ishikawa after the name of the Ishikawa-no-sho Manor, which was his place of origin in Settsu Province; or the other says he took the name from the manor he received which was called Ishikawa sho.
これは出身地摂津国に有する石川荘にちなんで地名を石川に改めたと云う説と、拝領した石川庄の地名を名乗ったとの説がある。