Estádio: Sub-Court B Round: 28 Ground: Hardcourt outdoor
| ITF - M25 Sapporo | 2023/09/16 01:00 | Shuichi Sekiguchi v Hikaru Shiraishi | 6-2,4-6,6-3 |
| ITF - M25 Sapporo | 2023/09/15 03:30 | Shuichi Sekiguchi v Jumpei Yamasaki | 6-3,7-5 |
| 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 |
| ITF - M25 Sapporo | 2023/09/16 01:00 | Kazuki Nishiwaki v Yuki Mochizuki | 6-1,6-3 |
| ITF - M25 Sapporo | 2023/09/15 03:20 | Kousuke Ogura v Kazuki Nishiwaki | 4-6,7-5,2-6 |
| ITF - M25 Sapporo | 2023/09/13 04:00 | Kazuki Nishiwaki v Taki Adachi | 6-1,6-2 |
| ITF - M25 Hong Kong | 2023/09/09 10:00 | Kazuki Nishiwaki v Coleman Wong | 2-6,7-5,8-10 |
| ITF - M25 Hong Kong | 2023/09/07 07:00 | Jie Cui v Kazuki Nishiwaki | 5-7,4-6 |
| ITF - M25 Hong Kong | 2023/09/06 02:00 | Collin Altamirano v Kazuki Nishiwaki | 3-6,5-7 |
| ITF - M25 Tainan | 2023/08/26 02:00 | Kazuki Nishiwaki v Rishab Agarwal | 5-7,3-6 |
| ITF - M25 Tainan | 2023/08/25 02:00 | Kazuki Nishiwaki v Yamato Sueoka | 6-2,6-3 |