Stadium: Sub-Court B Round: 26 Ground: Hardcourt outdoor
| ITF M25 Sapporo | 2023/09/08 02:30 | Shuichi Sekiguchi v Jumpei Yamasaki | 6-4,6-3 |
| ITF Japan F3 | 2018/03/19 01:00 | Shuichi Sekiguchi v Jumpei Yamasaki | 6-7,7-6,6-2 |
| ITF M25 Sapporo | 2023/09/13 01:00 | Shuichi Sekiguchi v Ryota Tanuma | 7-6,6-1 |
| ITF M25 Sapporo | 2023/09/10 02:00 | Shuichi Sekiguchi v Daisuke Sumizawa | 6-1,6-4 |
| ITF M25 Sapporo | 2023/09/09 02:00 | Naoki Nakagawa v Shuichi Sekiguchi | 7-5,3-6,5-7 |
| ITF M25 Sapporo | 2023/09/08 02:30 | Shuichi Sekiguchi v Jumpei Yamasaki | 6-4,6-3 |
| ITF M25 Sapporo | 2023/09/07 01:00 | Shuichi Sekiguchi v Chase Ferguson | 6-2,6-2 |
| ITF M25 Sapporo | 2023/09/05 04:20 | Shuichi Sekiguchi v Hiroki Sakagawa | 6-3,6-2 |
| 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 |
| ITF M25 Sapporo | 2023/09/08 02:30 | Shuichi Sekiguchi v Jumpei Yamasaki | 6-4,6-3 |
| ITF M25 Sapporo | 2023/09/05 02:00 | Jumpei Yamasaki v Kousuke Ogura | 6-4,6-4 |
| ITF M25 Jakarta | 2023/08/15 04:20 | Sora Fukuda v Jumpei Yamasaki | 7-5,6-4 |
| ITF M25 Jakarta | 2023/08/08 02:30 | Jeamoon Lee v Jumpei Yamasaki | 6-0,7-5 |
| ITF M25 Daegu | 2023/06/09 02:55 | Jumpei Yamasaki v Dominik Palan | 4-6,2-6 |
| ITF M25 Daegu | 2023/06/06 03:10 | Duckhee Lee v Jumpei Yamasaki | 1-6,6-4,4-6 |
| ITF M15 Karuizawa | 2023/06/03 03:30 | Sanhui Shin v Jumpei Yamasaki | 6-3,7-6 |
| ITF M15 Karuizawa | 2023/06/01 02:40 | Jumpei Yamasaki v Takuya Kumasaka | 6-3,6-2 |