| UTR Pro Noda | 2023/08/23 06:30 | Hiromasa Koyama v Yuta Tomida | 1-6,3-6 |
| UTR Pro Osaka | 2023/07/30 04:30 | Koki Ohnuma v Hiromasa Koyama | 6-3,5-2 |
| UTR Pro Osaka | 2023/07/28 06:54 | Hiromasa Koyama v Ryoma Matsushita | 1-6,2-6 |
| UTR Pro Osaka | 2023/07/27 06:00 | Hiromasa Koyama v Shu Matsuoka | 1-6,4-6 |
| UTR Pro Osaka | 2023/07/25 00:30 | Brody Nejedly-Krall v Hiromasa Koyama | 6-2,6-3 |
| UTR Pro Miki | 2023/02/12 00:30 | Hiromasa Koyama v Shion Itsusaki | 4-6,6-4,5-7 |
| UTR Pro Miki | 2023/02/10 03:30 | Yuji Arimura v Hiromasa Koyama | 3-6,3-6 |
| UTR Pro Miki | 2023/02/09 00:30 | Yuichiro Inui v Hiromasa Koyama | 7-5,6-1 |
| UTR Pro Noda | 2023/08/23 00:00 | Hiiro Sakamoto v Yuta Tomida | 1-6,7-6,1-6 |
| UTR Pro Miki | 2023/07/01 07:00 | Hiiro Sakamoto v Mizuki Kawada | 4-6,1-6 |
| UTR Pro Miki | 2023/06/30 00:30 | Hiiro Sakamoto v Taiyo Kurata | 3-6,7-5,6-0 |
| UTR Pro Miki | 2023/06/28 00:30 | Hiiro Sakamoto v Kento Tagashira | 6-3,6-2 |
| UTR Pro Miki | 2023/06/27 03:30 | Hiiro Sakamoto v Natsuki Yamamoto | 4-6,6-7 |
| UTR Pro Miki | 2023/06/26 00:30 | Sota Minami v Hiiro Sakamoto | 6-4,2-6,6-4 |
| UTR Pro Tennis Series Miki | 2022/12/09 02:00 | Hiiro Sakamoto v Kazuki Nishiwaki | 2-6,2-6 |
| UTR Pro Tennis Series Miki | 2022/12/06 02:00 | Hiiro Sakamoto v Ryohei Takase | 6-4,6-2 |