Ground: Synthetic outdoor
| ITF Japan F8 | 2014/06/27 01:00 | Keisuke Watanuki v Arata Onozawa | 3-6,4-6 |
| ITF Japan F5 | 2015/06/02 01:00 | Makoto Ochi v Arata Onozawa | 3-6,6-2,6-4 |
| ITF China F6 | 2015/05/26 07:20 | Arata Onozawa v Peng-Xiang Gong | 6-0,6-2 |
| ITF China F6 | 2015/05/20 02:00 | Arata Onozawa v Xi Qi | 4-6,1-6 |
| ITF Thailand F9 | 2015/05/06 03:00 | Arata Onozawa v Phassawit Bura'ritta | 6-2,0-6,5-7 |
| ITF Thailand F9 | 2015/05/05 04:25 | Arata Onozawa v Makoto Ochi | 6-3,6-3 |
| ITF Thailand F9 | 2015/04/29 04:55 | Warit Sornbutnark v Arata Onozawa | 6-3,6-2 |
| ITF Thailand F9 | 2015/04/28 07:15 | Masato Shiga v Arata Onozawa | 3-6,6-7 |
| ITF Japan F4 | 2015/03/30 05:00 | Arata Onozawa v Shuichi Sekiguchi | 4-6,4-6 |
| ITF Japan F6 | 2015/06/11 02:55 | Takuto Niki v Keisuke Watanuki | 6-7,7-6,6-4 |
| ITF Japan F6 | 2015/06/10 01:30 | Keisuke Watanuki v Hiromasa Oku | 6-2,6-3 |
| ITF Japan F5 | 2015/06/04 02:00 | Thomas Fancutt v Keisuke Watanuki | 7-5,7-6 |
| ITF Japan F5 | 2015/06/03 06:30 | Ryotaro Matsumura v Keisuke Watanuki | 6-2,4-6,0-6 |
| ITF Greece F9 | 2015/04/29 10:05 | David Simunek v Keisuke Watanuki | 6-4,6-2 |
| ITF Greece F5 | 2015/04/23 07:00 | Tom Kocevar-Desman v Keisuke Watanuki | 6-3,6-2 |
| ITF Greece F5 | 2015/04/21 10:40 | Charalampos Kapogiannis v Keisuke Watanuki | 6-3,1-6,5-7 |
| ITF Greece F4 | 2015/04/12 11:00 | Keisuke Watanuki v Stefan Frljanic | 6-4,2-6,5-7 |