Ishikawa has played the event well in previous years finishing 2nd and 3rd in two of his earlier attempts and although his form in the US this season has been mixed he clearly enjoys playing in his homeland.
Up against the latest rising star of Japan this week, Hideki Matsuyama, Ishikawa was more than equal to the task, coming from two shots off the 54 hole pace set by Oda to win in a playoff.
Matsuyama finished 17th after never really contending
Earlier in his career Ishikawa also won one of the other leading events in the northern island of Hokkaido, the Sun Chlorella Classic.
The pair finished three shots clear of Korean KT Kwon and Kazuhira Yamashita.
Kurt Barnes and Scott Strange finished as the leading Australians in a share of 8th position both players earning around A$46,000.
Brad Kennedy was the next best in a share of 17th.
Brendan Jones, in what is essentially his first full event since September of 2013 following wrist injury and surgery, finished a very creditable 44th.