South Korean Kyoung-Hoon Lee won the Invitational Sega Sammy Cup on Sunday, while Steve Conran finished as the leading Australian.
Lee closed with a seven-under-par fourth round of 65 to finish 19-under overall, some two shots clear of fellow South Korean Hyung-Sung Kim.
Kim finished with a 67, but that was no match for Lee as the rookie picked up his first victory on the Japanese Tour.
Ryo Ishikawa, Dong-Hwan Lee, Taichi Teshima and Katsumasa Miyamoto tied for third at 15 under, while Conran was well down the leaderboard in a share of 26th place.
Conran's final score of six under was one shot better than fellow Australian Brad Kennedy, who closed with a 70 to be tied for 32nd.
No other Australians managed to make the halfway cut.