# 2004 AIG Japan Open Tennis Championships – Men's singles

Rainer Schüttler was the defending champion, but did not participate.

## Seeds

All seeds receive a bye into the second round.
* Lleyton Hewitt (semifinals)
* David Nalbandian (third round)
* Andrei Pavel (second round)
* Paradorn Srichaphan (quarterfinals)
* Jiří Novák (champion)
* Guillermo Cañas (second round)
* Taylor Dent (final)
* Thomas Johansson (third round)
* Cyril Saulnier (quarterfinals)
* Hyung-Taik Lee (third round)
* Ricardo Mello (third round)
* Jarkko Nieminen (second round)
* Jan-Michael Gambill (third round)
* Dennis van Scheppingen (second round)
* Jan Hernych (second round)
* Gilles Müller (quarterfinals)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final | Final |
| 1 | Lleyton Hewitt | 7 | 6 | | | | | | | | | | | |
| 9 | Cyril Saulnier | 5 | 1 | | | | | | | | | | | |
| 9 | Cyril Saulnier | 5 | 1 | | 1 | Lleyton Hewitt | 4 | 6 | 2 | | | | | |
| | | | | | 5 | Jiří Novák | 6 | 4 | 6 | | | | | |
| 4 | Paradorn Srichaphan | 4 | 4 | | 5 | Jiří Novák | 6 | 4 | 6 | | | | | |
| 5 | Jiří Novák | 6 | 6 | | | | | | | | | | | |
| 5 | Jiří Novák | 6 | 6 | | | | | | | 5 | Jiří Novák | 5 | 6 | 6 |
| | | | | | | | | | | 7 | Taylor Dent | 7 | 1 | 3 |
| | Bohdan Ulihrach | 7 | 6 | | | | | | | | | | | | 7 | Taylor Dent | 7 | 1 | 3 |
| Q | Björn Phau | 5 | 4 | | | | | | | | | | | |
| Q | Björn Phau | 5 | 4 | | | Bohdan Ulihrach | 6 | 4 | 1 | | | | | |
| | | | | | 7 | Taylor Dent | 4 | 6 | 6 | | | | | |
| 7 | Taylor Dent | 6 | 4 | 6 | 7 | Taylor Dent | 4 | 6 | 6 | | | | | |
| 16 | Gilles Müller | 4 | 6 | 2 | | | | | | | | | | |

### Top half
#### Section 1

| First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | 1 | L Hewitt | 6 | 3 | 6 | | | | | | | | | |
| | G Weiner | 4 | 3 | WC | G Motomura | 0 | 6 | 1 | | | | | | | | | |
| WC | G Motomura | 6 | 6 | | | | | | 1 | L Hewitt | 6$^3$ | 6 | 6 | | | | |
| | A García | 6$^6$ | 6$^4$ | | | | | | WC | T Suzuki | 7$^7$ | 2 | 4 | | | | |
| WC | T Suzuki | 7$^8$ | 7$^7$ | WC | T Suzuki | 7$^7$ | 3 | 7 | | | | | | | | | |
| | | | | 15 | J Hernych | 6 | 6$^4$ | 5 | | | | | | | | | |
| | | | | | | | | | | | | | | 1 | L Hewitt | 7 | 6 |
| | | | | | | | | | | | | | | 9 | C Saulnier | 5 | 1 |
| | | | | 9 | C Saulnier | 2 | 6 | 6 | | | | | | | | | |
| Q | K Pless | 6$^2$ | 6$^0$ | | N Thomann | 6 | 1 | 4 | | | | | | | | | |
| | N Thomann | 7$^7$ | 7$^7$ | | | | | | 9 | C Saulnier | 6$^6$ | 7$^7$ | 7$^7$ | | | | |
| | C Rochus | 6$^R$ | | | | | | | 8 | T Johansson | 7$^8$ | 6$^3$ | 6$^5$ | | | | |
| | J Gimelstob | 6 | | | J Gimelstob | 4 | 4 | | | | | | | | | | |
| | | | | 8 | T Johansson | 6 | 6 | | | | | | | | | | |

#### Section 2

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 4 | P Srichaphan | 2 | 7$^7$ | 6 | | | | | | | | |
| | Y-h Lu | 6$^1$ | 6$^1$ | | | H Levy | 6 | 6$^3$ | 4 | | | | | | | | |
| | H Levy | 7$^7$ | 7$^7$ | | | | | | | 4 | P Srichaphan | 6 | 4 | | | | |
| | A Peya | 6 | 3 | 4 | | | | | | Q | M Chiudinelli | 3 | 1$^R$ | | | | |
| Q | M Chiudinelli | 4 | 6 | 6 | Q | M Chiudinelli | 6 | 7$^7$ | | | | | | | | | |
| | | | | | 14 | D van Scheppingen | 4 | 6$^3$ | | | | | | | | | |
| | | | | | | | | | | | | | | 4 | P Srichaphan | 4 | 4 |
| | | | | | | | | | | | | | | 5 | J Novák | 6 | 6 |
| | | | | | 11 | R Mello | 5 | 6 | 7$^7$ | | | | | | | | |
| | J Vacek | 3 | 4 | | | F Saretta | 7 | 2 | 6$^5$ | | | | | | | | |
| | F Saretta | 6 | 6 | | | | | | | 11 | R Mello | 1 | 2 | | | | |
| | G García López | 6 | 2 | 6 | | | | | | 5 | J Novák | 6 | 6 | | | | |
| | L Burgsmüller | 4 | 6 | 3 | | G García López | 5 | 2 | | | | | | | | | |
| | | | | | 5 | J Novák | 7 | 6 | | | | | | | | | |

### Bottom half
#### Section 3

| First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | 6 | G Cañas | 6 | 6$^2$ | 3 | | | | | | | | | |
| | K Carlsen | 5 | 2 | Q | M Kohlmann | 4 | 7$^7$ | 6 | | | | | | | | | |
| Q | M Kohlmann | | | | | | | | Q | M Kohlmann | 4 | 2 | | | | | |
| | B Ulihrach | 6 | 6 | | | | | | | B Ulihrach | 6 | 6 | | | | | |
| | N Okun | 4 | 1 | | B Ulihrach | 6 | 7$^7$ | | | | | | | | | | |
| | | | | 12 | J Nieminen | 3 | 6$^5$ | | | | | | | | | | |
| | | | | | | | | | | | | | | | B Ulihrach | 7 | 6 |
| | | | | | | | | | | | | | | Q | B Phau | 5 | 4 |
| | | | | 13 | J-M Gambill | 7$^7$ | 6 | | | | | | | | | | |
| Q | S Iwabuchi | 6 | 6 | | S Iwabuchi | 6$^5$ | 1 | | | | | | | | | | |
| WC | T Terachi | 1 | 3 | | | | | | 13 | J-M Gambill | 6$^1$ | 6 | 2 | | | | |
| Q | B Phau | 6 | 6 | | | | | | Q | B Phau | 7 | 2 | 6 | | | | |
| WC | T Iwami | 4 | 1 | Q | B Phau | 6 | 6 | | | | | | | | | | |
| | | | | 3 | A Pavel | 2 | 1 | | | | | | | | | | |

#### Section 4

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Third round | Third round | Third round | Third round | Third round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals |
| | | | | | 7 | T Dent | 6 | 6 | | | | | | | | | | | |
| | M Philippoussis | 3 | 4 | | | T Zíb | 3 | 4 | | | | | | | | | | | |
| | T Zíb | 6 | 6 | | | | | | | 7 | T Dent | 7 | 5 | 6 | | | | | |
| | W Arthurs | 6 | 7 | | | | | | | 10 | H-T Lee | 6$^4$ | 7 | 3 | | | | | |
| | J-R Lisnard | 4 | 5 | | | W Arthurs | 2 | 6$^2$ | | | | | | | | | | | |
| | | | | | 10 | H-T Lee | 6 | 7$^7$ | | | | | | | | | | | |
| | | | | | | | | | | | | | | | 7 | T Dent | 6 | 4 | 6 |
| | | | | | | | | | | | | | | | 16 | G Müller | 4 | 6 | 2 |
| | | | | | 16 | G Müller | 6 | 6 | | | | | | | | | | | |
| | A Bogomolov | 6 | 3 | 7$^7$ | | A Bogomolov | 3 | 1 | | | | | | | | | | | |
| | J Tipsarević | 3 | 6 | 6$^2$ | | | | | | 16 | G Müller | 7 | 3 | 6 | | | | | |
| Q | YT Wang | 6 | 7$^7$ | | | | | | | 2 | D Nalbandian | 6$^4$ | 6 | 4 | | | | | |
| | J Morrison | 3 | 6$^1$ | | | YT Wang | 6 | 6$^4$ | 2 | | | | | | | | | | |
| | | | | | 2 | D Nalbandian | 3 | 7 | 6 | | | | | | | | | | |