Stadium: Court 1 Round: 25 Ground: Hardcourt outdoor
| ITF M15 Kofu | 2019/03/22 02:00 | Issei Okamura v Ryota Tanuma | 4-6,2-6 |
| ITF China F1 | 2018/01/11 02:30 | Ryota Tanuma v Issei Okamura | 6-1,6-2 |
| ITF China F13 | 2016/07/22 05:20 | Ryota Tanuma v Issei Okamura | 3-6,6-7 |
| ITF Spain F14 | 2016/05/16 09:00 | Issei Okamura v Ryota Tanuma | 0-6,3-6 |
| ITF Chinese Taipei F1 | 2015/08/21 02:00 | Issei Okamura v Ryota Tanuma | 6-4,3-6,6-3 |
| ITF Japan F5 | 2015/06/01 04:10 | Issei Okamura v Ryota Tanuma | 6-7,4-6 |
| ITF M25 Nonthaburi | 2020/01/26 07:50 | Issei Okamura v Palaphoom Kovapitukted | 4-6,1-6 |
| ITF M15 Hong Kong | 2020/01/08 06:50 | Adam El Mihdawy v Issei Okamura | 4-6,6-2,6-3 |
| ITF M15 Hong Kong | 2020/01/07 02:00 | Issei Okamura v Chayanon Kaewsuto | 6-0,6-0 |
| ITF M15 Hong Kong | 2020/01/06 02:00 | Issei Okamura v Douglas Geiwald | 6-2,6-1 |
| ITF M15 Cancun | 2019/11/15 19:35 | Issei Okamura v Mariano Kestelboim | 4-6,1-6 |
| ITF M15 Cancun | 2019/11/05 16:35 | Mateus Alves v Issei Okamura | 6-3,6-2 |
| ITF M15 Changwon | 2019/10/15 03:10 | Cheong-Eui Kim v Issei Okamura | 6-4,4-6,6-4 |
| ITF M25 Toowoomba | 2019/10/08 01:50 | Issei Okamura v Tristan Schoolkate | 3-6,6-2,4-6 |
| Challenger Launceston | 2020/02/05 05:05 | Ryota Tanuma v Liam Broady | 3-6,2-6 |
| Challenger Launceston | 2020/02/03 23:00 | Ryota Tanuma v Tristan Schoolkate | 6-2,6-3 |
| Challenger Launceston | 2020/02/02 23:00 | Naoki Tajima v Ryota Tanuma | 6-2,6-2 |
| ITF M15 Hong Kong | 2020/01/09 03:25 | Makoto Ochi v Ryota Tanuma | 6-4,6-4 |
| ITF M15 Hong Kong | 2020/01/08 09:00 | Ryota Tanuma v Hanyi Liu | 6-2,6-3 |
| ITF M15 Nonthaburi | 2019/11/27 02:30 | Keisuke Saitoh v Ryota Tanuma | 6-2,7-6 |
| Challenger Kobe | 2019/11/05 04:15 | Jay Clarke v Ryota Tanuma | 6-3,3-6,6-3 |
| Challenger Kobe | 2019/11/04 06:30 | Ryota Tanuma v Takuto Niki | 6-3,4-6,7-6 |