Stadium: Court 3 Round: 54 Ground: Hardcourt outdoor
| ITF M15 Anseong | 2019/06/26 04:30 | Sung Hun Kim v Ren Nakamura | 7-6,1-6,6-0 |
| ITF M15 Gimcheon | 2019/06/18 01:00 | Ren Nakamura v Minjong Park | 5-7,6-7 |
| ITF M15 Gimcheon | 2019/06/17 01:00 | Ren Nakamura v Sam Ryan Ziegann | 2-6,6-2,10-7 |
| ITF M15 Karuizawa | 2019/05/30 06:15 | Gengo Kikuchi v Ren Nakamura | 6-2,6-2 |
| ITF M15 Karuizawa | 2019/05/29 04:20 | Ren Nakamura v Winter Meagher | 6-3,6-2 |
| ITF M15 Cancun | 2019/05/07 19:45 | Ren Nakamura v Jesse Flores | 2-6,2-6 |
| ITF M25 Matsuyama | 2019/04/09 01:00 | Sho Shimabukuro v Ren Nakamura | 6-4,6-1 |
| ITF M15 Kashiwa | 2019/04/01 00:00 | Kaito Uesugi v Ren Nakamura | 6-2,6-2 |
| ITF M25 Taipei | 2019/07/15 04:30 | Mu Fu Tsai v Seita Watanabe | 0-6,0-6 |
| ITF M15 Gimcheon | 2019/06/18 03:20 | Seita Watanabe v Seong Taek Im | 3-6,7-6,12-14 |
| ITF M15 Gimcheon | 2019/06/12 03:20 | Seong-Gook Oh v Seita Watanabe | 6-7,6-2,6-3 |
| ITF M15 Gimcheon | 2019/06/11 02:50 | Seita Watanabe v Hyung-Chan Lim | 6-4,6-0 |
| ITF M15 Gimcheon | 2019/06/10 02:00 | Seita Watanabe v Jin Sung Han | 6-1,6-2 |
| ITF M15 Daegu | 2019/06/06 02:00 | Jung-Woong Na v Seita Watanabe | 6-3,6-2 |
| ITF M15 Daegu | 2019/06/05 03:55 | Seita Watanabe v Issei Okamura | 6-4,7-6 |
| ITF M15 Daegu | 2019/06/04 02:20 | Seita Watanabe v Seung-Hun Shin | 6-0,6-1 |