Kazuya Hirabayashi is tied in the series against
Itaru Ishida, 2-2-1.
| event |
round |
table |
player one |
result |
player two |
| Grand Prix Sendai 2001 | 13 | 1 | Hirabayashi, Kazuya (1853) | ID | Ishida, Itaru (1893) |
| Grand Prix Utsunomiya 2002 | 11 | 17 | Hirabayashi, Kazuya (1768) | Won 2-0 | Ishida, Itaru (1868) |
| Grand Prix Okayama 2004 | 6 | 2 | Hirabayashi, Kazuya (1685) | Lost 0-2 | Ishida, Itaru (2000) |
| Grand Prix Okayama 2004 | Q | | Hirabayashi, Kazuya (1743) | Lost 0-2 | Ishida, Itaru (2046) |
| Grand Prix Matsuyama 2005 | 9 | 6 | Hirabayashi, Kazuya (2010) | Won 2-0 | Ishida, Itaru (1948) |