Stadium: Hard 21 Round: 25 Ground: Hardcourt outdoor
| ITF - M15 Héraklion | 2021/05/20 06:30 | Niki, Takuto v Zhang, Ze | 5-7,3-6 |
| ITF - M15 Héraklion | 2021/05/19 09:45 | Niki, Takuto v Mark Whitehouse | 6-3,6-3 |
| ITF - M15 Sharm El Sheikh | 2021/04/07 12:45 | Uzhylovsky, Vladimir v Niki, Takuto | 7-6,3-6,6-4 |
| ITF - M15 Sharm El Sheikh | 2021/04/01 09:25 | Niki, Takuto v Bega, Alessandro | 3-6,3-6 |
| ITF - M15 Sharm El Sheikh | 2021/03/31 12:05 | Niki, Takuto v Fares Zakaria | 6-2,6-4 |
| ITF - M15 Sharm El Sheikh | 2021/03/25 07:30 | Niki, Takuto v Marek Gengel | 1-6,0-6 |
| ITF - M15 Sharm El Sheikh | 2021/03/24 07:30 | Toby Martin v Niki, Takuto | 2-6,2-6 |
| ITF - M15 Sharm El Sheikh | 2021/03/18 09:40 | Makoto Ochi v Niki, Takuto | 6-3,6-2 |
| ITF - M15 Héraklion | 2021/05/25 06:30 | Federico Arnaboldi v Matthew Dellavedova | 6-2,6-3 |
| ITF - M15 Héraklion | 2021/05/24 06:30 | Federico Arnaboldi v Vasiliauskas, Matas | 6-3,6-0 |
| ITF - M15 Héraklion | 2021/05/23 06:30 | Federico Arnaboldi v Johann, Lars | 6-1,6-2 |
| ITF - M15 Antalya | 2021/04/23 08:25 | Federico Arnaboldi v Frunza, Nicolae | 3-6,2-6 |
| ITF - M15 Antalya | 2021/04/22 08:30 | Yshai Oliel v Federico Arnaboldi | 3-6,4-6 |
| ITF - M15 Antalya | 2021/04/21 10:00 | Peter Fajta v Federico Arnaboldi | 3-6,4-6 |
| ITF - M15 Antalya | 2021/04/20 07:00 | Federico Arnaboldi v Ivan Sergeyev | 6-2,7-6 |
| ITF - M15 Antalya | 2021/04/19 09:00 | Federico Arnaboldi v Minarik, Kristof | 6-4,6-2 |