Stadium: I Round: 27 Ground: Hardcourt outdoor
| ITF Japan F1 | 2018/03/08 01:30 | Naoki Nakagawa v Gengo Kikuchi | 7-5,7-6 |
| ITF Japan F1 | 2018/03/06 02:00 | Naoki Nakagawa v Shin Yoshida | 6-4,6-1 |
| Challenger Kyoto Qual | 2018/02/18 02:45 | Naoki Nakagawa v Ko Suzuki | 6-7,6-7 |
| Challenger Kyoto Qual | 2018/02/17 02:25 | Hiroki Moriya v Naoki Nakagawa | 6-4,6-7,2-6 |
| ITF USA F6 | 2018/02/01 17:55 | Naoki Nakagawa v Tim Van Rijthoven | 4-6,3-6 |
| ITF USA F6 | 2018/01/30 15:00 | Naoki Nakagawa v Danny Thomas | 6-3,6-4 |
| ITF USA F5 | 2018/01/24 15:00 | Naoki Nakagawa v Roberto Cid Subervi | 2-6,3-6 |
| ITF USA F4 | 2018/01/21 17:00 | Naoki Nakagawa v Julien Cagnina | 7-6,3-6,3-6 |
| ITF Japan F1 | 2018/03/08 05:40 | Rio Noguchi v Daniel Nguyen | 4-6,3-6 |
| ITF Japan F1 | 2018/03/07 05:30 | Shoma Kato v Daniel Nguyen | 0-6,2-6 |
| Challenger Yokohama | 2018/03/01 02:00 | Daniel Nguyen v Stephane Robert | 5-7,0-6 |
| Challenger Yokohama | 2018/02/27 05:35 | Daniel Nguyen v Yosuke Watanuki | 6-2,6-4 |
| Challenger Yokohama Qual | 2018/02/26 01:00 | Hiroki Moriya v Daniel Nguyen | 6-2,6-3 |
| Challenger Yokohama Qual | 2018/02/25 02:20 | Yuta Shimizu v Daniel Nguyen | 6-4,5-7,2-6 |
| Challenger Yokohama Qual | 2018/02/24 06:35 | Nasa Hatakeyama v Daniel Nguyen | 1-6,3-6 |
| ITF Egypt F5 | 2018/02/16 12:00 | Jaimee Floyd Angele v Daniel Nguyen | 6-7,6-2,6-3 |