Stadium: Court 4 Round: 62 Ground: Hardcourt outdoor
| ITF M15 Kashiwa | 2019/04/02 05:50 | Taisei Ichikawa v Issei Okamura | 7-5,5-7,5-7 |
| ITF Hong Kong F3 | 2018/12/24 02:00 | Issei Okamura v Taisei Ichikawa | 6-2,7-5 |
| ITF M15 Sintra | 2020/09/13 10:00 | Arnaud Bovy v Issei Okamura | 6-0,6-0 |
| ITF M15 Sintra | 2020/09/07 10:00 | Joao Lucas Reis da Silva v Issei Okamura | 7-5,7-6 |
| ITF M15 Sintra | 2020/09/06 10:00 | Tennyson Whiting v Issei Okamura | 4-6,4-6 |
| ITF M15 Sharm El Sheikh | 2020/03/11 08:00 | Issei Okamura v Noah Thurner | 6-1,6-4 |
| ITF M15 Sharm El Sheikh | 2020/03/03 08:00 | Issei Okamura v Volodymyr Uzhylovskyi | 7-6,4-6,6-10 |
| ITF M15 Sharm El Sheikh | 2020/02/26 08:00 | Issei Okamura v Ryota Tanuma | 3-6,2-6 |
| ITF M15 Sharm El Sheikh | 2020/02/25 08:00 | Issei Okamura v Phuong Van Nguyen | 6-3,4-6,10-6 |
| ITF M15 Sharm El Sheikh | 2020/02/24 09:00 | Issei Okamura v Ismael C R Mzai | 6-3,3-6,10-5 |
| ITF M15 Nonthaburi | 2019/11/26 07:20 | Taisei Ichikawa v Ji Sung Nam | 5-7,2-6 |
| Challenger Kobe | 2019/11/07 02:00 | Yosuke Watanuki v Taisei Ichikawa | 6-2,6-1 |
| Challenger Kobe | 2019/11/06 04:45 | Taisei Ichikawa v Enrique Lopez-Perez | 5-7,6-2,7-6 |
| Challenger Kobe | 2019/11/05 02:45 | Timur Khabibulin v Taisei Ichikawa | 0-6,2-6 |
| ITF M15 Nanchang | 2019/10/04 04:40 | Ye Cong Mo v Taisei Ichikawa | 7-5,4-6,6-3 |
| ITF M15 Nanchang | 2019/10/03 05:00 | Natthasith Kunsuwan v Taisei Ichikawa | 0-6,6-7 |
| ITF M15 Nanchang | 2019/10/01 02:00 | Tianjia Guo v Taisei Ichikawa | 0-6,0-6 |
| ITF M15 Nanchang | 2019/09/27 04:10 | Taisei Ichikawa v Takashi Saito | 4-6,6-2,3-6 |