Stadium: Court 3 Round: 25 Ground: Hardcourt indoor
| Challenger Yokkaichi | 2019/08/05 05:05 | Shintaro Imai v Naoki Tajima | 6-2,6-3 |
| Nonthaburi, Singles M-ITF-THA-01A | 2019/07/25 07:10 | Naoki Tajima v Yuta Shimizu | 0-6,4-6 |
| Nonthaburi, Singles M-ITF-THA-01A | 2019/07/24 02:00 | Niki Kaliyanda Poonacha v Naoki Tajima | 4-6,6-4,1-6 |
| Saarlouis, Singles Qualifying M-ITF-GER-07A | 2019/07/02 12:00 | Naoki Tajima v Boehler, Dominik | 2-6,2-6 |
| ITF M15 Kamen | 2019/06/26 11:30 | Naoki Tajima v Staeheli, Luca | 5-7,0-6 |
| Balatonalmadi, Singles Qualifying M-ITF-HUN-02A | 2019/06/19 09:50 | Ryan Nijboer v Naoki Tajima | 6-3,6-2 |
| Irpin, Singles Qualifying M-ITF-UKR-04A | 2019/05/28 07:00 | Oleg Prihodko v Naoki Tajima | 6-0,6-1 |
| Irpin, Singles Qualifying M-ITF-UKR-04A | 2019/05/21 12:40 | Nikita Mashtakov v Naoki Tajima | 6-0,7-6 |
| ITF M15 Helsinki | 2019/08/21 10:55 | Antinheimo, Oskar v Niklas-Salminen, Patrick | 2-6,2-6 |