Stadium: Center Court A Round: 25 Ground: Hardcourt outdoor
| ITF M25 Tainan | 2023/08/23 04:20 | Ergi Kirkin v Seita Watanabe | 4-6,7-6,6-3 |
| ITF M25 Tainan | 2023/08/15 02:00 | Seita Watanabe v Takuya Kumasaka | 3-6,6-4,2-6 |
| ITF M25 Astana | 2023/08/03 10:50 | Khumoyun Sultanov v Seita Watanabe | 4-6,6-3,7-5 |
| ITF M25 Astana | 2023/08/02 10:25 | Seita Watanabe v Timur Maulenov | 3-6,6-3,6-2 |
| ITF M25 Astana | 2023/08/01 05:20 | Seita Watanabe v Mykhailo Mossur | 6-4,6-3 |
| ITF M25 Astana | 2023/07/31 05:40 | Seita Watanabe v Vitaliy Zatsepin | 6-2,6-2 |
| Challenger Astana | 2023/07/23 10:35 | Seita Watanabe v Egor Agafonov | 2-6,2-6 |
| ITF M15 Monastir | 2023/07/19 14:20 | Seita Watanabe v Gilbert S K Junior | 2-6,6-2,2-6 |
| ITF M25 Hong Kong | 2023/08/30 02:00 | Kasidit Samrej v Tatsuma Ito | 6-1,6-4 |
| Challenger Winnipeg | 2023/08/14 16:00 | Kiranpal Pannu v Tatsuma Ito | 7-5,4-6,6-1 |
| Challenger Winnipeg | 2023/08/13 16:00 | Keegan Rice v Tatsuma Ito | 4-6,5-7 |
| Challenger 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 |
| ITF M15 Karuizawa | 2023/06/03 03:30 | Kazuma Kawachi v Tatsuma Ito | 1-6,4-6 |
| ITF M15 Karuizawa | 2023/06/01 03:20 | Preston Brown v Tatsuma Ito | 3-6,0-6 |