Round: 27 Ground: Hardcourt outdoor
| ITF Japan F8 | 2015/06/27 01:00 | Yasutaka Uchiyama v Katsuki Nagao | 7-6,6-3 |
| ITF Japan F8 | 2015/06/25 04:25 | Hiroyasu Ehara v Katsuki Nagao | 4-6,3-6 |
| ITF Japan F8 | 2015/06/24 01:10 | Katsuki Nagao v Masaki Osafune | 6-3,6-0 |
| ITF Japan F7 | 2015/06/18 02:00 | Ryota Tanuma v Katsuki Nagao | 6-3,6-1 |
| ITF Japan F7 | 2015/06/17 01:00 | Shunrou Takeshima v Katsuki Nagao | 6-7,3-6 |
| ITF Japan F6 | 2015/06/10 01:30 | Yosuke Watanuki v Katsuki Nagao | 7-6,6-7,6-4 |
| ITF Japan F5 | 2015/06/02 01:00 | Ben Mclachlan v Katsuki Nagao | 6-1,6-2 |
| ITF Guam F1 | 2015/05/30 02:20 | Takao Suzuki v Katsuki Nagao | 2-6,6-4,6-2 |
| ITF Germany F17 | 2015/10/22 11:00 | Niels Lootsma v Marc Sieber | 5-7,6-4,6-3 |
| ITF Germany F17 | 2015/10/20 09:00 | Goncalo Oliveira v Marc Sieber | 3-6,4-6 |
| ITF Germany F15 | 2015/10/08 13:30 | Marc Sieber v Dominik Boehler | 5-7,7-5,2-6 |
| ITF Germany F14 | 2015/10/04 11:00 | Maximilian Marterer v Marc Sieber | 6-2,6-2 |
| ITF Germany F14 | 2015/10/03 11:00 | Marc Sieber v Tom Schonenberg | 4-6,6-3,6-3 |
| ITF Germany F14 | 2015/10/02 11:00 | Marc Sieber v Martins Podzus | 6-4,6-4 |
| ITF Germany F14 | 2015/10/01 13:20 | Marc Sieber v Bernd Kossler | 6-1,6-1 |
| ITF Germany F14 | 2015/09/30 10:10 | Marc Sieber v Pavel Nejedly | 6-3,6-4 |