Page 4 de l'historique des matchs du joueur de tennis: Retrouvez ici la totalité des matchs et tournois joués par Hiromasa Koyama.
77 matchs enregistrés.
| 03/08/2025 | M15 Singapore | Hiromasa Koyama vs. Jaden Dewandaka Tan |
| 10/07/2025 | M15 Tokyo | Jake Delaney vs. Hiromasa Koyama |
| 08/07/2025 | M15 Tokyo | Kyle Seelig vs. Hiromasa Koyama |
| 03/07/2025 | M15 Tokyo | Hiromasa Koyama vs. Hikaru Shiraishi |
| 01/07/2025 | M15 Tokyo | Hiromasa Koyama vs. Tai Sach |
| 01/04/2025 | M15 Kashiwa | Daisuke Sumizawa vs. Hiromasa Koyama |
| 26/03/2025 | M15 Tsukuba | Hiromasa Koyama vs. Yusuke Takahashi |
| 18/03/2025 | M15 Nishi-Tokyo | Hiromasa Koyama vs. Tai Sach |
| 12/03/2025 | M15 Hinode | Yuta Kawahashi vs. Hiromasa Koyama |
| 19/01/2025 | Australian Open (juniors) | Hiromasa Koyama vs. Andres Santamarta Roig |
| 08/09/2024 | M25 Sapporo | Kohei Hayashi vs. Hiromasa Koyama |
| 05/09/2024 | M25 Sapporo | Hiromasa Koyama vs. Keisuke Saitoh |
| 03/09/2024 | M25 Sapporo | Hyeon Chung vs. Hiromasa Koyama |
| 10/07/2024 | M15 Tokyo | Kenta Miyoshi vs. Hiromasa Koyama |
| 03/07/2024 | M15 Tokyo | Hiromasa Koyama vs. Ryotaro Matsumura |
| 11/03/2024 | M15 Hinode | Hong Kit Wong vs. Hiromasa Koyama |
| 10/03/2024 | M15 Hinode | Hiromasa Koyama vs. Ryouga Kanno |