Stadium: Court 6 Round: 25 Ground: Hardcourt outdoor
| ITF M15 Akishima | 2019/06/14 03:15 | Rio Noguchi v Keisuke Saitoh | 6-1,6-1 |
| ITF M15 Akishima | 2019/06/13 04:05 | Keisuke Saitoh v Gengo Kikuchi | 7-5,6-0 |
| ITF M15 Akishima | 2019/06/12 02:40 | Keisuke Saitoh v Kyohei Yamanaka | 6-1,6-3 |
| ITF M15 Kashiwa | 2019/04/04 01:00 | Yusuke Takahashi v Keisuke Saitoh | 6-2,6-1 |
| ITF M15 Kofu | 2019/03/19 01:00 | Keisuke Saitoh v Jumpei Yamasaki | 2-6,3-6 |
| ITF M15 Nishi-Tokyo | 2019/03/13 01:00 | Shuichi Sekiguchi v Keisuke Saitoh | 6-3,6-2 |
| ITF M15 Nishi-Tama | 2019/03/08 02:40 | Seong Chan Hong v Keisuke Saitoh | 6-3,6-0 |
| ITF M15 Nishi-Tama | 2019/03/06 01:00 | Soichiro Moritani v Keisuke Saitoh | 2-6,0-6 |
| Challenger Kobe | 2019/11/05 04:15 | Jay Clarke v Ryota Tanuma | 6-3,3-6,6-3 |
| Challenger Kobe | 2019/11/04 06:30 | Ryota Tanuma v Takuto Niki | 6-3,4-6,7-6 |
| ITF M15 Changwon | 2019/10/16 05:40 | Ryota Tanuma v Shintaro Mochizuki | 3-6,1-6 |
| ITF M15 Nanchang | 2019/09/22 03:00 | Ryota Tanuma v Dusty H. Boyer | 6-3,6-4 |
| ITF M15 Nanchang | 2019/09/21 04:55 | Makoto Ochi v Ryota Tanuma | 2-6,6-1,3-6 |
| ITF M15 Nanchang | 2019/09/20 03:30 | Ryota Tanuma v Vinayak Sharma Kaza | 6-4,6-1 |
| ITF M15 Nanchang | 2019/09/19 03:45 | Ryota Tanuma v Prithvi Sekhar | 6-0,6-0 |
| ITF M15 Nanchang | 2019/09/18 02:00 | Ryota Tanuma v Oleg Khotkov | 2-6,6-3,7-5 |