| ITF Japan F6 Qual | 2015/06/08 01:00 | Ryota Kishi v Koichi Sano | 2-6,0-6 |
| ITF Japan F6 Qual | 2015/06/07 05:00 | Koichi Sano v Keisuke Numajiri | 6-0,4-6,6-1 |
| ITF Japan F5 | 2015/06/02 03:15 | Hiromasa Oku v Koichi Sano | 6-4,3-6,6-2 |
| 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 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 | 2015/05/03 04:00 | Kelsey Stevenson v Issei Okamura | 6-7,4-6 |
| ITF Thailand F9 | 2015/05/02 07:30 | Issei Okamura v Ken Onoda | 6-2,6-4 |
| ITF China F4 | 2015/04/21 04:35 | Chuhan Wang v Issei Okamura | 6-4,6-4 |