Ground: Hardcourt outdoor
| ITF Thailand F9 | 2015/06/14 04:25 | Issei Okamura v Zach Itzstein | 6-3,5-7,5-7 |
| ITF Japan F6 | 2015/06/11 01:00 | Issei Okamura v Duckhee Lee | 1-6,4-6 |
| ITF Japan F6 | 2015/06/09 04:00 | Koichi Sano v Issei Okamura | 2-6,4-6 |
| ITF Japan F6 Qual | 2015/06/08 01:00 | Yuichiro Inui v Issei Okamura | 3-6,1-6 |
| ITF Japan F5 | 2015/06/01 04:10 | Issei Okamura v Ryota Tanuma | 6-7,4-6 |
| ITF Japan F5 | 2015/05/30 01:00 | Issei Okamura v Shota Iino | 6-3,2-6,6-4 |
| ITF Thailand F9 | 2015/05/06 06:35 | Tyler Hochwalt v Issei Okamura | 6-3,1-6,6-2 |
| ITF Thailand F9 | 2015/05/05 11:00 | Sidharth Rawat v Issei Okamura | 4-6,7-5,6-7 |
| ITF Thailand F9 | 2015/06/20 03:00 | Teeradon Tortrakul v Garry Tokas | 6-2,6-2 |
| ITF Thailand F9 | 2015/04/18 06:30 | Teeradon Tortrakul v Suthinan Tanthaseraneewat | 1-6,7-6,0-6 |