Stadium: Sub Court B Round: 25 Ground: Hardcourt outdoor
| Challenger Zhangjiagang | 2023/08/28 10:15 | Shuichi Sekiguchi v Jie Cui | 1-6,2-6 |
| Challenger Zhangjiagang | 2023/08/27 06:25 | Shuichi Sekiguchi v Francis Casey Alcantara | 7-5,6-3 |
| Challenger Zhuhai | 2023/08/22 07:00 | Dominik Palan v Shuichi Sekiguchi | 7-6,5-7,6-2 |
| Challenger Zhuhai | 2023/08/21 03:00 | Shuichi Sekiguchi v Markos Kalovelonis | 7-6,2-6,6-4 |
| ITF M25 Astana | 2023/08/05 07:45 | Yusuke Takahashi v Shuichi Sekiguchi | 6-4,6-4 |
| ITF M25 Astana | 2023/08/04 08:45 | Shuichi Sekiguchi v Egor Agafonov | 7-6,6-1 |
| ITF M25 Astana | 2023/08/03 07:15 | Shuichi Sekiguchi v S D Prajwal Dev | 6-7,7-5,6-0 |
| ITF M25 Astana | 2023/08/02 05:40 | Ajeet Rai v Shuichi Sekiguchi | 2-6,1-6 |
| ITF M25 Sapporo | 2023/09/04 00:55 | Hiroki Sakagawa v Omar Fields | 5-7,6-3,13-11 |
| ITF M25 Sapporo | 2023/09/03 01:00 | Naoki Tajima v Hiroki Sakagawa | 2-6,3-6 |
| ITF M25 Anseong | 2023/06/21 03:40 | Hiroki Sakagawa v Duckhee Lee | 1-6,2-6 |
| ITF M25 Anseong | 2023/06/19 05:25 | Seung Woo Cho v Hiroki Sakagawa | 6-1,1-6,6-10 |
| ITF M25 Anseong | 2023/06/19 01:00 | Hyun Woo Cho v Hiroki Sakagawa | 6-4,2-6,4-10 |
| ITF M25 Anseong | 2023/06/18 01:00 | Hiroki Sakagawa v Jungmin Hwang | 6-0,6-2 |
| UTR Pro Tennis Series Texas | 2022/08/20 18:00 | Franco Ribero v Hiroki Sakagawa | 7-6,5-0 |
| UTR Pro Tennis Series Texas | 2022/08/18 19:30 | Hiroki Sakagawa v Alex Koong | 6-2,5-2 |