Stadium: Court 10 Round: 29 Ground: Hardcourt outdoor
| ITF - M15 Kashiwa | 2019/04/03 05:20 | Niki, Takuto v Sekiguchi, Shuichi | 2-6,6-3,7-6 |
| ITF - M15 Nishi-Tokyo | 2019/03/16 01:00 | Niki, Takuto v Sekiguchi, Shuichi | 4-6,7-6,3-6 |
| Matsuyama, Singles M-ITF-JPN-06A | 2019/04/13 03:00 | Niki, Takuto v Wishaya Trongcharoenchaikul | 7-5,6-3 |
| Matsuyama, Singles M-ITF-JPN-06A | 2019/04/12 04:00 | Brymer, Gage v Niki, Takuto | 4-6,5-7 |
| Matsuyama, Singles M-ITF-JPN-06A | 2019/04/12 01:00 | Niki, Takuto v Yuki Mochizuki | 6-2,6-3 |
| Matsuyama, Singles M-ITF-JPN-06A | 2019/04/10 03:30 | Niki, Takuto v Katayama, Sho | 6-2,6-3 |
| ITF - M15 Kashiwa | 2019/04/04 02:35 | Tanaka, Yunosuke v Niki, Takuto | 7-6,1-6,6-1 |
| ITF - M15 Kashiwa | 2019/04/03 05:20 | Niki, Takuto v Sekiguchi, Shuichi | 2-6,6-3,7-6 |
| ITF - M15 Tsukuba | 2019/03/28 02:10 | Tagata, Ryohei v Niki, Takuto | 3-6,6-2,7-5 |
| ITF - M15 Tsukuba | 2019/03/27 01:00 | Niki, Takuto v Saito, Takashi | 6-4,6-2 |
| Matsuyama, Singles M-ITF-JPN-06A | 2019/04/13 01:00 | Hong, Seong Chan v Sekiguchi, Shuichi | 2-6,3-6 |
| Matsuyama, Singles M-ITF-JPN-06A | 2019/04/12 05:20 | Naoki Tajima v Sekiguchi, Shuichi | 4-6,4-6 |
| Matsuyama, Singles M-ITF-JPN-06A | 2019/04/12 02:25 | Issei Okamura v Sekiguchi, Shuichi | 1-6,0-6 |
| Matsuyama, Singles M-ITF-JPN-06A | 2019/04/09 04:10 | Tanuma, Ryota v Sekiguchi, Shuichi | 4-6,4-6 |
| ITF - M15 Kashiwa | 2019/04/03 05:20 | Niki, Takuto v Sekiguchi, Shuichi | 2-6,6-3,7-6 |
| ITF - M15 Nishi-Tokyo | 2019/03/17 02:00 | Sekiguchi, Shuichi v Hong, Seong Chan | 6-7,4-6 |
| ITF - M15 Nishi-Tokyo | 2019/03/16 01:00 | Niki, Takuto v Sekiguchi, Shuichi | 4-6,7-6,3-6 |
| ITF - M15 Nishi-Tokyo | 2019/03/15 01:00 | Sekiguchi, Shuichi v Shintaro Imai | 6-3,6-0 |