Stadium: Court 4 Round: 25 Ground: Hardcourt outdoor
| Challenger Busan | 2023/05/08 02:00 | Daisuke Sumizawa v Woobin Shin | 6-2,3-6,2-6 |
| Challenger Gwangju | 2023/04/30 04:10 | Daniel Masur v Daisuke Sumizawa | 6-0,6-4 |
| ITF M25 Kashiwa | 2023/04/06 01:30 | Daisuke Sumizawa v Yunseong Chung | 2-6,2-6 |
| ITF M25 Kashiwa | 2023/04/05 03:15 | Ryotaro Taguchi v Daisuke Sumizawa | 6-7,7-6,6-7 |
| ITF M25 Tsukuba | 2023/03/30 02:50 | Hiroki Moriya v Daisuke Sumizawa | 7-5,6-1 |
| ITF M25 Tsukuba | 2023/03/29 03:30 | Daisuke Sumizawa v Makoto Ochi | 1-6,7-5,6-4 |
| ITF M25 Canberra | 2023/03/21 02:50 | Jordan Smith v Daisuke Sumizawa | 6-4,7-6 |
| ITF M25 Canberra | 2023/03/14 00:20 | Dane Sweeny v Daisuke Sumizawa | 7-6,6-4 |
| ITF M15 Doboj | 2023/05/09 08:00 | Taiyo Yamanaka v Radomir Tomic | 2-6,6-7 |
| ITF M15 Doboj | 2023/05/08 08:00 | Taiyo Yamanaka v Federico Mirgone | 6-0,6-0 |
| ITF M25 Kashiwa | 2023/04/03 01:00 | Renta Tokuda v Taiyo Yamanaka | 6-0,7-5 |
| ITF M25 Kashiwa | 2023/04/02 00:30 | Ko Suzuki v Taiyo Yamanaka | 1-6,6-3,11-13 |
| ITF M25 Tsukuba | 2023/03/27 00:30 | Taiyo Yamanaka v Naoki Tajima | 6-4,5-7,8-10 |
| ITF M15 Monastir | 2023/03/09 08:30 | Hady Habib v Taiyo Yamanaka | 6-3,6-3 |
| ITF M15 Monastir | 2023/03/08 08:30 | Tomasz Berkieta v Taiyo Yamanaka | 6-4,3-6,3-6 |
| ITF M15 Monastir | 2023/03/06 13:30 | Taiyo Yamanaka v Aoran Wang | 6-3,6-2 |