Stadium: Court 1 Round: 25 Ground: Hardcourt outdoor
| ITF - M15 Monastir | 2021/08/19 07:30 | Brymer, Gage v Naoki Tajima | 6-3,6-3 |
| ITF - M15 Monastir | 2021/08/17 08:30 | Naoki Tajima v Connor, Preston | 6-1,6-0 |
| ITF - M15 Monastir | 2021/08/12 14:50 | Sho Shimabukuro v Naoki Tajima | 6-1,7-6 |
| ITF - M15 Monastir | 2021/08/11 19:05 | Adas, Seif v Naoki Tajima | 2-6,3-6 |
| ITF M15 Castelo Branco | 2021/07/27 12:10 | Naoki Tajima v Breysach , Martin | 6-3,2-6,2-6 |
| ITF M25 Idanha-A-Nova | 2021/07/20 10:45 | Anton Matusevich v Naoki Tajima | 6-3,7-5 |
| ITF M25 Idanha-A-Nova | 2021/07/15 09:30 | Rodrigues, Daniel v Naoki Tajima | 6-3,7-5 |
| ITF M25 Idanha-A-Nova | 2021/07/14 09:25 | Coelho, Fabio v Naoki Tajima | 6-4,4-6,2-6 |
| ITF - M15 Monastir | 2021/08/24 07:30 | Kawahashi, Yuta v Fabrizio Andaloro | 6-4,6-1 |
| ITF - M15 Monastir | 2021/08/22 08:30 | Kawahashi, Yuta v Credit Chaiyarin | 6-2,6-3 |
| ITF - M15 Monastir | 2021/08/18 07:30 | Kawahashi, Yuta v Seelig, Kyle | 6-1,4-6,6-7 |
| ITF - M15 Monastir | 2021/08/17 07:30 | Kawahashi, Yuta v Adil Kalyanpur | 6-1,6-1 |
| ITF - M15 Monastir | 2021/08/15 11:00 | Kawahashi, Yuta v Tomohiro Masabayashi | 6-3,6-3 |
| ITF - M15 Monastir | 2021/08/10 07:30 | Beale, Jeremy v Kawahashi, Yuta | 6-4,6-3 |
| ITF - M15 Monastir | 2021/08/09 08:30 | Favero, Lorenzo v Kawahashi, Yuta | 1-6,2-6 |
| ITF - M15 Monastir | 2021/08/08 10:30 | Josh Reid v Kawahashi, Yuta | 3-6,1-6 |