Round: 25 Ground: Hardcourt outdoor
| ITF M15 Anning | 2019/01/10 04:30 | Issei Okamura v Naoki Tajima | 6-4,3-6,4-6 |
| ITF M15 Kofu | 2019/03/22 02:00 | Issei Okamura v Ryota Tanuma | 4-6,2-6 |
| ITF M15 Kofu | 2019/03/21 02:00 | Takuya Kumasaka v Issei Okamura | 1-6,2-6 |
| ITF M15 Kofu | 2019/03/19 02:50 | Aoran Wang v Issei Okamura | 2-6,6-4,4-6 |
| ITF M15 Nishi-Tokyo | 2019/03/13 05:25 | Rimpei Kawakami v Issei Okamura | 6-2,6-1 |
| ITF M15 Nishi-Tokyo | 2019/03/12 01:00 | Issei Okamura v Hikaru Shiraishi | 6-2,6-3 |
| ITF M15 Nishi-Tokyo | 2019/03/11 02:00 | Issei Okamura v Li-Wei Tan | 6-4,6-0 |
| ITF M25 Mildura | 2019/03/07 02:00 | Issei Okamura v Shuichi Sekiguchi | 3-6,6-3,2-6 |
| ITF M25 Mildura | 2019/03/05 23:00 | Issei Okamura v Aaron Addison | 7-5,6-2 |
| ITF M15 Kofu | 2019/03/21 03:40 | Yusuke Takahashi v Naoki Tajima | 6-3,6-2 |
| ITF M15 Kofu | 2019/03/20 02:25 | Naoki Tajima v Tomohiro Masabayashi | 4-6,6-1,6-2 |
| ITF M15 Nishi-Tokyo | 2019/03/13 03:50 | Shintaro Imai v Naoki Tajima | 6-1,6-4 |
| ITF M15 Nishi-Tama | 2019/03/08 04:30 | Sho Shimabukuro v Naoki Tajima | 6-3,7-5 |
| ITF M15 Nishi-Tama | 2019/03/05 05:25 | Naoki Tajima v Shinji Hazawa | 7-5,6-3 |
| ITF M15 Anning | 2019/01/18 03:00 | Yan Bai v Naoki Tajima | 3-6,6-1,6-0 |
| ITF M15 Anning | 2019/01/17 03:00 | Naoki Tajima v Michael Zhu | 6-2,6-3 |
| ITF M15 Anning | 2019/01/15 02:00 | Naoki Tajima v Liran Chen | 6-2,6-1 |