Estadio: Indoor A Round: 25 Ground: Hardcourt outdoor
| ITF M25 Sapporo | 2023/09/11 00:55 | Naoki Tajima v Ko Suzuki | 7-6,4-6,10-8 |
| ITF M25 Sapporo | 2023/09/03 01:00 | Naoki Tajima v Hiroki Sakagawa | 2-6,3-6 |
| ITF M25 Tainan | 2023/08/22 02:00 | Naoki Tajima v Leonid Sheyngezikht | 3-6,5-7 |
| ITF M25 Tainan | 2023/08/17 02:00 | Ergi Kirkin v Naoki Tajima | 6-3,6-4 |
| ITF M25 Tainan | 2023/08/15 01:55 | Yu Hsiang Su v Naoki Tajima | 3-6,1-6 |
| ITF M15 Caloundra | 2023/07/31 23:50 | Naoki Tajima v Anton Shepp | 6-1,4-6,7-10 |
| ITF M15 Caloundra | 2023/07/25 23:50 | Naoki Tajima v Brandon Walkin | 6-7,6-3,4-6 |
| ITF M15 Caloundra | 2023/07/25 00:00 | Naoki Tajima v Jesse Delaney | 6-2,6-2 |
| ITF M25 Sapporo | 2023/09/07 03:00 | Ryotaro Matsumura v Tatsuma Ito | 7-6,6-4 |
| ITF M25 Sapporo | 2023/09/06 03:35 | Seita Watanabe v Tatsuma Ito | 6-4,4-6,4-6 |
| ITF M25 Hong Kong | 2023/08/30 02:00 | Kasidit Samrej v Tatsuma Ito | 6-1,6-4 |
| Challenger de Winnipeg | 2023/08/14 16:00 | Kiranpal Pannu v Tatsuma Ito | 7-5,4-6,6-1 |
| Challenger de Winnipeg | 2023/08/13 16:00 | Keegan Rice v Tatsuma Ito | 4-6,5-7 |
| Challenger de Cary | 2023/08/06 14:00 | Fons Van Sambeek v Tatsuma Ito | 7-6,1-6,6-3 |
| ITF M15 Karuizawa | 2023/06/04 02:00 | Yuta Kawahashi v Tatsuma Ito | 7-5,6-2 |
| ITF M15 Karuizawa | 2023/06/03 07:00 | Sora Fukuda v Tatsuma Ito | 6-7,6-7 |