Stadium: Court 1 Round: 25 Ground: Hardcourt outdoor
| ITF Japan F1 | 2018/03/10 02:00 | Takashi Saito v Wishaya Trongcharoenchaikul | 4-6,7-5,4-6 |
| ITF Japan F1 | 2018/03/08 03:10 | Yuichi Ito v Takashi Saito | 2-6,4-6 |
| ITF Japan F1 | 2018/03/07 01:00 | Takashi Saito v Makoto Ochi | 6-3,2-6,6-4 |
| ITF Japan F1 | 2018/03/05 01:00 | Takashi Saito v Itsuki Matsumoto | 6-3,6-4 |
| ITF Japan F1 | 2018/03/03 03:00 | Takashi Saito v Tamaki Yamao | 7-6,6-4 |
| ITF Hong Kong F6 | 2018/01/03 03:30 | Matteo Viola v Takashi Saito | 4-6,6-2,6-4 |
| ITF Hong Kong F6 | 2018/01/01 02:00 | Ming Chun Alan Sou v Takashi Saito | 2-6,1-6 |
| ITF Hong Kong F5 | 2017/12/28 02:00 | Takashi Saito v Alexander Zhurbin | 6-7,4-6 |
| ITF Japan F1 | 2018/03/09 02:00 | Naoki Nakagawa v Daniel Nguyen | 6-3,3-6,5-7 |
| 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 |