Stadium: Court 9 Round: 45 Ground: Hardcourt outdoor
| ITF M15 - Tsukuba | 2019/03/28 01:00 | Ryota Tanuma v Shintaro Imai | 5-7,3-6 |
| ITF M15 - Tsukuba | 2019/03/26 01:00 | Aoran Wang v Ryota Tanuma | 6-7,5-7 |
| ITF M15 - Kofu | 2019/03/23 02:55 | Jumpei Yamasaki v Ryota Tanuma | 6-2,6-4 |
| ITF M15 - Kofu | 2019/03/22 02:00 | Issei Okamura v Ryota Tanuma | 4-6,2-6 |
| ITF M15 - Kofu | 2019/03/21 04:15 | Ryota Tanuma v Kento Takeuchi | 6-4,6-4 |
| ITF M15 - Kofu | 2019/03/20 01:00 | Yunosuke Tanaka v Ryota Tanuma | 6-2,3-6,4-6 |
| ITF M15 - Nishi-Tokyo | 2019/03/14 01:00 | Ryota Tanuma v Blake Ellis | 1-6,2-6 |
| ITF M15 - Nishi-Tokyo | 2019/03/13 05:55 | Kousuke Ogura v Ryota Tanuma | 2-6,6-7 |
| ITF M15 - Kofu | 2019/03/20 07:15 | Seita Watanabe v Sho Katayama | 3-6,2-6 |
| ITF M15 - Kofu | 2019/03/18 06:30 | Keigo Shimizu v Seita Watanabe | 1-6,1-6 |
| ITF M15 - Kofu | 2019/03/18 03:00 | Seita Watanabe v Shao-Fan Liu | 6-3,4-6,11-9 |
| ITF M15 - Nishi-Tokyo | 2019/03/12 05:00 | Makoto Ochi v Seita Watanabe | 6-1,6-2 |
| Challenger Kobe | 2018/11/11 06:10 | Blake Ellis v Seita Watanabe | 6-4,6-2 |
| Challenger Kobe | 2018/11/10 07:20 | Seita Watanabe v Takashi Saito | 4-6,7-5,7-6 |
| ITF Japan F8 | 2018/06/09 01:00 | Seita Watanabe v Tomohiro Masabayashi | 7-6,5-7,4-6 |
| Challenger Kobe Qual | 2017/11/04 07:45 | Seita Watanabe v Xin Gao | 6-4,4-6,0-6 |