| UTR Pro Kawaguchi | 2024/06/22 01:00 | Christopher Kosei Ono v Seiya Nakanishi | 7-6,3-6,3-6 |
| UTR Pro Kawaguchi | 2024/08/14 00:00 | Emon Van Loben Sels v Christopher Kosei Ono | 6-2,6-4 |
| UTR Pro Kawaguchi | 2024/08/13 03:30 | Daisuke Sumizawa v Christopher Kosei Ono | 6-2,6-1 |
| UTR Pro Kawaguchi | 2024/06/22 09:31 | Christopher Kosei Ono v Ryoma Mishiro | 0-6,1-6 |
| UTR Pro Kawaguchi | 2024/06/22 01:00 | Christopher Kosei Ono v Seiya Nakanishi | 7-6,3-6,3-6 |
| UTR Pro Kawaguchi | 2024/06/19 07:40 | Christopher Kosei Ono v Payton Jim on | 6-1,5-0 |
| UTR Pro Kawaguchi | 2024/06/19 01:30 | Christopher Kosei Ono v Hikaru Shiraishi | 1-6,1-6 |
| UTR Pro Kawaguchi | 2024/06/17 00:00 | Taiyo Kurata v Christopher Kosei Ono | 4-6,6-1,6-7 |
| UTR Pro Urayasu | 2024/05/11 03:15 | Kotaro Mochizuki v Christopher Kosei Ono | 6-3,6-4 |
| UTR Pro Kawaguchi | 2024/08/13 03:30 | Emon Van Loben Sels v Seiya Nakanishi | 6-3,6-1 |
| UTR Pro Kawaguchi | 2024/08/12 03:30 | Seiya Nakanishi v Mao Takada | 6-4,6-2 |
| ITF M15 Tokyo | 2024/07/09 00:55 | Seiya Nakanishi v Yusaku Sugaya | 2-6,2-6 |
| ITF M15 Tokyo | 2024/07/08 03:30 | Naoki Tajima v Seiya Nakanishi | 3-6,6-3,6-10 |
| UTR Pro Kawaguchi | 2024/06/29 07:30 | Elijah Cham v Seiya Nakanishi | 1-6,6-4,6-4 |
| UTR Pro Kawaguchi | 2024/06/29 01:00 | Kosuke Nakanishi v Seiya Nakanishi | 6-4,1-6,4-6 |
| UTR Pro Kawaguchi | 2024/06/27 03:27 | Tomislav E Papac v Seiya Nakanishi | 3-6,1-6 |
| UTR Pro Kawaguchi | 2024/06/25 01:30 | Ryotaro Matsumura v Seiya Nakanishi | 6-1,6-0 |