Stadium: Court 10 Round: 26 Ground: Hardcourt outdoor
| ITF M25 Mildura | 2019/03/07 02:00 | Issei Okamura v Shuichi Sekiguchi | 3-6,6-3,2-6 |
| ITF China F5 | 2016/04/14 03:00 | Issei Okamura v Shuichi Sekiguchi | 2-6,2-6 |
| ITF M25 Matsuyama | 2019/04/10 07:00 | Jumpei Yamasaki v Issei Okamura | 6-4,5-7,1-6 |
| ITF M25 Matsuyama | 2019/04/09 02:40 | Issei Okamura v Shota Iino | 6-2,6-2 |
| ITF M15 Kashiwa | 2019/04/04 01:00 | Issei Okamura v Jumpei Yamasaki | 3-6,2-6 |
| ITF M15 Kashiwa | 2019/04/02 05:50 | Taisei Ichikawa v Issei Okamura | 7-5,5-7,5-7 |
| ITF M15 Tsukuba | 2019/03/27 03:25 | Issei Okamura v Naoki Tajima | 3-6,4-6 |
| ITF M15 Kofu | 2019/03/22 02:00 | Issei Okamura v Ryota Tanuma | 4-6,2-6 |
| ITF M15 Kofu | 2019/03/21 02:00 | Takuya Kumasaka v Issei Okamura | 1-6,2-6 |
| ITF M15 Kofu | 2019/03/19 02:50 | Aoran Wang v Issei Okamura | 2-6,6-4,4-6 |
| ITF M25 Matsuyama | 2019/04/09 04:10 | Ryota Tanuma v Shuichi Sekiguchi | 4-6,4-6 |
| ITF M15 Kashiwa | 2019/04/03 05:20 | Takuto Niki v Shuichi Sekiguchi | 2-6,6-3,7-6 |
| ITF M15 Nishi-Tokyo | 2019/03/17 02:00 | Shuichi Sekiguchi v Seong Chan Hong | 6-7,4-6 |
| ITF M15 Nishi-Tokyo | 2019/03/16 01:00 | Takuto Niki v Shuichi Sekiguchi | 4-6,7-6,3-6 |
| ITF M15 Nishi-Tokyo | 2019/03/15 01:00 | Shuichi Sekiguchi v Shintaro Imai | 6-3,6-0 |
| ITF M15 Nishi-Tokyo | 2019/03/14 03:45 | Shuichi Sekiguchi v Yuki Mochizuki | 6-2,6-1 |
| ITF M15 Nishi-Tokyo | 2019/03/13 01:00 | Shuichi Sekiguchi v Keisuke Saitoh | 6-3,6-2 |
| ITF M25 Mildura | 2019/03/09 01:00 | Shuichi Sekiguchi v Brydan Klein | 7-6,1-6,1-6 |