Stadium: Court 1 Round: 19 Ground: Hardcourt indoor
| 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 |
| UTR Pro Kawaguchi | 2024/06/24 05:39 | Seiya Nakanishi v Haruki Katsushima | 6-1,6-3 |
| UTR Pro Kawaguchi | 2024/06/22 05:39 | Seiya Nakanishi v Kosuke Nakanishi | 0-6,5-7 |
| UTR Pro Kawaguchi | 2024/06/22 01:00 | Christopher Kosei Ono v Seiya Nakanishi | 7-6,3-6,3-6 |
| ITF M15 Tokyo | 2024/07/08 03:30 | Hiroki Sakagawa v Yusaku Sugaya | 4-6,5-7 |
| ITF M15 Karuizawa | 2024/06/01 06:10 | Yusaku Sugaya v Kaichi Uchida | 1-6,1-6 |
| ITF M15 Karuizawa | 2024/06/01 01:30 | Yusaku Sugaya v Woobin Shin | 7-6,4-6,10-8 |
| ITF M15 Karuizawa | 2024/05/30 02:50 | Kokoro Isomura v Yusaku Sugaya | 4-6,6-1,6-7 |
| ITF M15 Karuizawa | 2024/05/29 02:00 | Yusaku Sugaya v Shunsuke Nakagawa | 5-7,7-6,10-7 |
| ITF M15 Karuizawa | 2024/05/27 01:00 | Geni Inoue v Yusaku Sugaya | 4-6,2-6 |
| ITF M15 Karuizawa | 2024/05/26 01:00 | Yusaku Sugaya v Yua Taka | 6-7,7-5,10-5 |