Ground: Hardcourt outdoor
| ITF M25 Sapporo | 2024/09/08 01:00 | Kohei Hayashi v Hiromasa Koyama | 6-2,6-4 |
| ITF M25 Sapporo | 2024/09/05 03:10 | Hiromasa Koyama v Keisuke Saitoh | 0-6,6-4,3-6 |
| ITF M25 Sapporo | 2024/09/03 03:00 | Hyeon Chung v Hiromasa Koyama | 5-7,1-6 |
| ITF M15 Tokyo | 2024/07/10 06:15 | Kenta Miyoshi v Hiromasa Koyama | 6-1,6-2 |
| ITF M15 Tokyo | 2024/07/03 03:30 | Hiromasa Koyama v Ryotaro Matsumura | 4-6,5-7 |
| ITF M15 Hinode | 2024/03/11 01:00 | Hiromasa Koyama v Hong Kit Wong | 7-6,3-6,4-10 |
| UTR Pro Noda | 2023/08/26 00:00 | Hiromasa Koyama v Paul Howe | 6-7,6-7 |
| UTR Pro Noda | 2023/08/25 00:00 | Hiromasa Koyama v Hiiro Sakamoto | 1-6,1-6 |
| Challenger Brisbane | 2025/01/26 03:30 | Tai Leonard Sach v Leo Vithoontien | 1-6,1-6 |
| ITF M15 Tauranga | 2024/12/18 23:10 | Tai Leonard Sach v Alexander Klintcharov | 5-7,4-6 |
| ITF M15 Tauranga | 2024/12/18 02:20 | Tai Leonard Sach v Corban Crowther | 6-4,6-4 |
| ITF M15 Wellington | 2024/12/14 20:55 | Tai Leonard Sach v Ajeet Rai | 4-6,2-6 |
| ITF M15 Wellington | 2024/12/13 22:00 | Matt Kuhar v Tai Leonard Sach | 6-3,2-6,0-6 |
| ITF M15 Wellington | 2024/12/12 23:05 | Tai Leonard Sach v Jack Loutit | 7-6,0-6,7-5 |
| ITF M15 Wellington | 2024/12/11 20:55 | Derek Pham v Tai Leonard Sach | 4-6,5-7 |
| ITF M15 Wellington | 2024/12/10 20:55 | Elijah Cham v Tai Leonard Sach | 4-6,7-6,2-6 |