(D)：Difending Champion
| Date | Championships | Course | Venue | Champion | |
| 5/13 – 5/14 | 12th 2004 Japan Women’s Senior Golf Championship | Chiba Country Club Noda Course | CHIBA | Chizuko Yajima | |
| 6/22 – 6/26 | 46th 2004 Japan Women’s Amateur Golf Championship | Rokkokokusai Golf Club East/Center Course | HYOGO | Mika Miyazato | |
| 7/6 – 7/10 | 89th 2004 Japan Amateur Golf Championship | Ryugasaki Country Club | IBARAKI | Dong-Hwan Lee | |
| 8/18 – 8/20 | 10th 2004 Japan Junior Golf Championship Boy’s 15-17 Division | Kasumigaseki Country Club West Course | SAITAMA | Shintaro Kobayashi | |
| 8/19 – 8/20 | 10th 2004 Japan Junior Golf Championship Boy’s 12-14 Division | Kasumigaseki Country Club East Course | SAITAMA | Shunta Maeawakura | |
| 8/19 – 8/20 | 10th 2004 Japan Junior Golf Championship Girs’s 15-17 Division | Kasumigaseki Country Club East Course | SAITAMA | Nozomi Sato | |
| 8/19 – 8/20 | 10th 2004 Japan Junior Golf Championship Girl’s 12-14 Division | Kasumigaseki Country Club East Course | SAITAMA | Mika Miyazato | |
| 8/24 – 8/27 | 58th 2004 Japan Collegiate Golf Championship | ABC Golf Club | HYOGO | Kiteku Gon | |
| 8/25 – 8/27 | 41st 2004 Japan Women’s Collegiate Golf Championship | ABC Golf Club | HYOGO | Chiharu Tsunekawa | |
| 9/30 – 10/3 |  |
37th 2004 Japan Women’s Open Golf Championship | Hiroshima Country Club Hachihonmatsu Course | HIROSHIMA | Yuri Fudo |
| 10/14 – 10/17 | |
69th 2004 Japan Open Golf Championship | Katayamazu Golf Club Hakusan Course | ISHIKAWA | Toru Taniguchi |
| 10/28 – 10/31 | |
14th 2004 Japan Senior Open Golf Championship | Ibaraki Golf Club East Course | IBARAKI | Katsunari Takahashi |
| 11/8 – 11/9 | 11th 2004 Japan Mid-Senior Golf Championship | Nagoya Golf Club | AICHI | Isao Takahashi | |
| 11/8 – 11/9 | 11th 2004 Japan Grand-Senior Golf Championship | Nagoya Golf Club | AICHI | Keizo Tsuchida | |
| 11/10 – 11/12 | 26th 2004 Japan Senior Golf Championship | Miyoshi Country Club West Course | AICHI | Tetsuo Sakata | |
| 11/17 – 11/19 | 9th 2004 Japan Mid-Amateur Golf Championship | Matsuyama Seaside Coutry Club | EHIME | Kosei Iida | |
| 11/18 – 11/19 | 9th 2004 Japan Women’s Mid-Amateur Golf Championship | Hakuho Country Club | CHIBA | Kagami Takahashi | |