| ITF Guam F1 | 2015/05/29 00:00 | Hiromasa Oku v Takao Suzuki | 6-4,6-7,5-7 |
| ITF Guam F1 | 2015/05/27 00:00 | Hiromasa Oku v Masayoshi Ono | 6-0,6-2 |
| ITF Guam F1 | 2015/05/26 00:00 | Hiromasa Oku v Masaki Sasai | 6-1,6-1 |
| ITF Thailand F9 | 2015/04/28 03:00 | Yuichi Ito v Hiromasa Oku | 6-4,2-6,4-6 |
| ITF Thailand F9 | 2015/04/22 07:50 | Hiromasa Oku v Yong-Kyu Lim | 3-6,1-6 |
| ITF Thailand F9 | 2015/04/20 03:00 | Jacob Grills v Hiromasa Oku | 6-2,3-6,1-6 |
| ITF Japan F3 | 2015/03/21 02:30 | Hiromasa Oku v Kaito Uesugi | 6-4,6-4 |
| ITF Japan F2 | 2015/03/16 01:00 | Yutaro Matsuzaki v Hiromasa Oku | 6-2,3-6,7-6 |
| ITF Guam F1 | 2015/05/28 00:00 | Koichi Sano v Ko Suzuki | 2-6,1-6 |
| ITF Guam F1 | 2015/05/26 03:40 | Matias Franco Descotte v Koichi Sano | 2-6,6-7 |
| ITF Japan F6 Qual | 2014/06/09 03:00 | Keisuke Watanuki v Koichi Sano | 6-4,6-0 |
| ITF Japan F6 Qual | 2014/06/07 00:00 | Yusei Fukuoka v Koichi Sano | 0-6,2-6 |
| ITF Japan F5 | 2014/06/03 02:30 | Koichi Sano v Yuya Kibi | 4-6,2-6 |
| ITF Guam F1 | 2014/05/27 02:45 | Jeevan Nedunchezhiyan v Koichi Sano | 6-2,6-4 |