Stadium: Court 3 Round: 27 Ground: Hardcourt outdoor
| ITF China F1 | 2018/01/11 02:30 | Tanuma, Ryota v Issei Okamura | 6-1,6-2 |
| ITF China F13 | 2016/07/22 05:20 | Tanuma, Ryota v Issei Okamura | 3-6,6-7 |
| ITF Spain F14 | 2016/05/16 09:00 | Issei Okamura v Tanuma, Ryota | 0-6,3-6 |
| ITF Chinese Taipei F1 | 2015/08/21 02:00 | Issei Okamura v Tanuma, Ryota | 6-4,3-6,6-3 |
| ITF Japan F5 | 2015/06/01 04:10 | Issei Okamura v Tanuma, Ryota | 6-7,4-6 |
| Kofu, Qualifications Simples M-ITF-JPN-03A | 2019/03/21 02:00 | Takuya Kumasaka v Issei Okamura | 1-6,2-6 |
| Kofu, Qualifications Simples M-ITF-JPN-03A | 2019/03/19 02:50 | Aoran Wang v Issei Okamura | 2-6,6-4,4-6 |
| ITF - M15 Nishi-Tokyo | 2019/03/13 05:25 | Kawakami, Rimpei v Issei Okamura | 6-2,6-1 |
| ITF - M15 Nishi-Tokyo | 2019/03/12 01:00 | Issei Okamura v Hikaru Shiraishi | 6-2,6-3 |
| ITF - M15 Nishi-Tokyo | 2019/03/11 02:00 | Issei Okamura v Tan, Li-Wie | 6-4,6-0 |
| ITF - M25 Mildura | 2019/03/07 02:00 | Issei Okamura v Sekiguchi, Shuichi | 3-6,6-3,2-6 |
| ITF - M25 Mildura | 2019/03/05 23:00 | Issei Okamura v Addison, Aaron | 7-5,6-2 |
| Albury, Simples M-ITF-AUS-01A | 2019/02/27 23:30 | Issei Okamura v Crnokrak, Alexander | 3-6,2-6 |
| Kofu, Qualifications Simples M-ITF-JPN-03A | 2019/03/21 04:15 | Tanuma, Ryota v Takeuchi, Kento (1987) | 6-4,6-4 |
| Kofu, Qualifications Simples M-ITF-JPN-03A | 2019/03/20 01:00 | Tanaka, Yunosuke v Tanuma, Ryota | 6-2,3-6,4-6 |
| ITF - M15 Nishi-Tokyo | 2019/03/14 01:00 | Tanuma, Ryota v Blake Ellis | 1-6,2-6 |
| ITF - M15 Nishi-Tokyo | 2019/03/13 05:55 | Kousuke Ogura v Tanuma, Ryota | 2-6,6-7 |
| ITF - M15 Nishi-Tokyo | 2019/03/12 03:20 | Tanuma, Ryota v Katayama, Sho | 6-4,2-6,10-5 |
| ITF - M15 Nishi-Tokyo | 2019/03/11 01:00 | Tanuma, Ryota v Liu, Shao-Fan | 7-6,6-3 |
| ITF - M25 Mildura | 2019/03/05 02:25 | Adamson, Alec v Tanuma, Ryota | 2-6,6-1,7-6 |
| Albury, Simples M-ITF-AUS-01A | 2019/02/28 01:45 | Klein, Brydan v Tanuma, Ryota | 6-3,6-2 |