# 2012 All Japan Indoor Tennis Championships – Singles

Dominik Meffert was the defending champion but decided not to participate. Tatsuma Ito won the title, defeating Malek Jaziri 6–7$^{(5–7)}$, 6–1, 6–2 in the final.

## Seeds

* Go Soeda (second round)
* Malek Jaziri (final)
* Tatsuma Ito (champion)
* Yuichi Sugita (quarterfinals)
* Danai Udomchoke (second round)
* Yang Tsung-hua (second round)
* Benjamin Mitchell (first round)
* Harri Heliövaara (second round)

## 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

| Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final | Final |
| | Hiroki Moriya | 4 | 2 | | | | | |
| 3 | Tatsuma Ito | 6 | 6 | | | | | |
| 3 | Tatsuma Ito | 6 | 6 | 3 | Tatsuma Ito | 6$^5$ | 6 | 6 |
| | | | | 2 | Malek Jaziri | 7$^7$ | 1 | 2 |
| | Samuel Groth | 6$^2$ | 3 | 2 | Malek Jaziri | 7$^7$ | 1 | 2 |
| 2 | Malek Jaziri | 7$^7$ | 6 | | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | G Soeda | 6 | 6 | | | | | | | | | | | | | | | |
| Q | P Raja | 4 | 4 | | 1 | G Soeda | 6$^9$ | 1 | | | | | | | | | | |
| WC | Y Uchiyama | 5 | 1 | | | Hiroki Moriya | 7$^{11}$ | 6 | | | | | | | | | | |
| | Hiroki Moriya | 7 | 6 | | | | | | | | Hiroki Moriya | 6 | 5 | 7$^7$ | | | | |
| | S Rieschick | 6 | 6 | | | | | | | | S Rieschick | 4 | 7 | 6$^5$ | | | | |
| | A Weintraub | 4 | 4 | | | S Rieschick | 6 | 6 | | | | | | | | | | |
| | Z Zhang | 1 | 6 | 3 | 6 | T-h Yang | 2 | 0 | | | | | | | | | | |
| 6 | T-h Yang | 6 | 3 | 6 | | | | | | | | | | | | Hiroki Moriya | 4 | 2 |
| 3 | T Ito | 7$^7$ | 7 | | | | | | | | | | | | 3 | T Ito | 6 | 6 |
| | J Lemke | 6$^2$ | 5 | | 3 | T Ito | 3 | 6 | 6 | | | | | | | | | |
| | R Klaasen | 6$^4$ | 7$^8$ | 4 | Q | M Barton | 6 | 4 | 0 | | | | | | | | | |
| Q | M Barton | 7$^7$ | 6$^6$ | 6 | | | | | | 3 | T Ito | 7$^7$ | 6$^4$ | 6 | | | | |
| | Y Bhambri | 6 | 6 | | | | | | | | Y Bhambri | 6$^5$ | 7$^7$ | 3 | | | | |
| | C Niland | 1 | 3 | | | Y Bhambri | 3 | 6 | 6 | | | | | | | | | |
| WC | T Niki | 5 | 3 | | 5 | D Udomchoke | 6 | 4 | 2 | | | | | | | | | |
| 5 | D Udomchoke | 7 | 6 | | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 8 | H Heliövaara | 7 | 6 | | | | | | | | | | | | | | | |
| WC | Shota Tagawa | 5 | 4 | | 8 | H Heliövaara | 4 | 6 | 6$^5$ | | | | | | | | | |
| | S Groth | 1 | 6 | 7 | | S Groth | 6 | 4 | 7$^7$ | | | | | | | | | |
| Q | B Klein | 6 | 3 | 5 | | | | | | | S Groth | 7$^7$ | 7$^{12}$ | | | | | |
| | Y-k Lim | 3 | 4 | | | | | | | 4 | Y Sugita | 6$^4$ | 6$^{10}$ | | | | | |
| WC | T Suzuki | 6 | 5$^r$ | | | Y-k Lim | 5 | 2 | | | | | | | | | | |
| | T Chen | 6$^3$ | 3 | | 4 | Y Sugita | 7 | 6 | | | | | | | | | | |
| 4 | Y Sugita | 7$^7$ | 6 | | | | | | | | | | | | | S Groth | 6$^2$ | 3 |
| 7 | B Mitchell | 7 | 2 | 4 | | | | | | | | | | | 2 | M Jaziri | 7$^7$ | 6 |
| | J Wang | 5 | 6 | 6 | | J Wang | 6 | 2 | 6 | | | | | | | | | |
| | J Millman | 6$^9$ | 5 | | | K Čapkovič | 1 | 6 | 3 | | | | | | | | | |
| | K Čapkovič | 7$^{11}$ | 7 | | | | | | | | J Wang | 6 | 4 | 3 | | | | |
| | Michael Look | 6 | 7$^7$ | | | | | | | 2 | M Jaziri | 0 | 6 | 6 | | | | |
| Q | Y Chu-huan | 4 | 6$^4$ | | | M Look | 5 | 5 | | | | | | | | | | |
| | D Molchanov | 7$^9$ | 6$^5$ | 0 | 2 | M Jaziri | 7 | 7 | | | | | | | | | | |
| 2 | M Jaziri | 6$^7$ | 7$^7$ | 6 | | | | | | | | | | | | | | |