Stadium: Sub Court B Round: 25 Ground: Hardcourt outdoor
| ITF M25 Hong Kong | 2023/08/31 02:00 | Naoki Nakagawa v Keisuke Saitoh | 6-4,6-7,6-1 |
| ITF M25 Hong Kong | 2023/08/30 02:00 | Keisuke Saitoh v Ji Hoon Son | 6-3,7-6 |
| ITF M15 Caloundra | 2023/08/04 00:55 | Isaac Becroft v Keisuke Saitoh | 6-3,6-4 |
| ITF M15 Caloundra | 2023/08/03 00:50 | Tai Leonard Sach v Keisuke Saitoh | 2-6,1-6 |
| ITF M15 Caloundra | 2023/08/01 04:50 | Keisuke Saitoh v Edward Winter | 7-6,6-2 |
| ITF M15 Caloundra | 2023/07/27 00:00 | Isaac Becroft v Keisuke Saitoh | 5-7,6-2,6-1 |
| ITF M15 Caloundra | 2023/07/25 03:30 | Matthew Burton v Keisuke Saitoh | 3-6,2-6 |
| ITF M25 Anseong | 2023/06/20 02:00 | Keisuke Saitoh v Yeongseok Jeong | 6-7,4-6 |
| ITF M25 Sapporo | 2023/09/04 01:00 | Tomohiro Masabayashi v Chih Chi Huang | 6-3,6-3 |
| ITF M25 Tainan | 2023/08/24 02:00 | Ergi Kirkin v Tomohiro Masabayashi | 6-4,6-3 |
| ITF M25 Tainan | 2023/08/23 04:55 | Chien Hsun Lo v Tomohiro Masabayashi | 7-5,5-7,3-6 |
| ITF M25 Tainan | 2023/08/17 02:00 | Tomohiro Masabayashi v Makoto Ochi | 6-7,1-6 |
| ITF M15 Jakarta | 2023/06/27 05:00 | Nathan Anthony Barki v Tomohiro Masabayashi | 6-2,6-4 |
| ITF M15 Jakarta | 2023/06/17 02:00 | Omar Jasika v Tomohiro Masabayashi | 6-1,6-1 |
| ITF M15 Jakarta | 2023/06/15 03:15 | Hong-Lin Fu v Tomohiro Masabayashi | 2-6,7-5,6-7 |
| ITF M25 Jakarta | 2023/06/06 05:10 | Tomohiro Masabayashi v Omar Jasika | 0-6,2-6 |