Katsuhiro Mori trails the series against
Masashi Oiso, 3-4.
| event |
round |
table |
player one |
result |
player two |
| Grand Prix Okayama 2004 | 5 | 25 | Mori, Katsuhiro (1897) | Lost 1-2 | Oiso, Masashi (1883) |
| Grand Prix Singapore 2005 | 11 | 22 | Mori, Katsuhiro (1938) | Won 2-1 | Oiso, Masashi (2010) |
| Grand Prix Niigata 2005 | 13 | 9 | Mori, Katsuhiro (2019) | Lost 0-2 | Oiso, Masashi (2215) |
| Grand Prix Beijing 2005 | 8 | 11 | Mori, Katsuhiro (2041) | Won 2-0 | Oiso, Masashi (2196) |
| Grand Prix Hiroshima 2006 | 14 | 3 | Mori, Katsuhiro (1963) | Won 2-0 | Oiso, Masashi (1906) |
| Grand Prix Kitakyushu 2009 | 6 | 13 | Mori, Katsuhiro (1996) | Lost 1-2 | Oiso, Masashi (1889) |
| Grand Prix Kitakyushu 2009 | Q | | Mori, Katsuhiro (2046) | Lost 1-2 | Oiso, Masashi (1980) |