Stadium: Court 1 Round: 62 Ground: Hardcourt outdoor
| ITF M15 Sharm El Sheikh | 2020/02/24 10:00 | Amr Asrawy v Ken Onishi | 4-6,6-0,10-8 |
| ITF M15 Sharm El Sheikh | 2020/02/17 09:00 | Piotr Grynkowski v Ken Onishi | 6-1,6-4 |
| ITF M15 Hong Kong | 2020/01/08 09:30 | Makoto Ochi v Ken Onishi | 7-6,6-2 |
| ITF M15 Hong Kong | 2020/01/07 04:45 | Kousuke Ogura v Ken Onishi | 5-7,4-6 |
| ITF M15 Hong Kong | 2020/01/06 02:00 | Shohei Chikami v Ken Onishi | 4-6,1-6 |
| ITF M15 Te Anau | 2019/12/30 23:00 | Elliot Benchetrit v Ken Onishi | 7-5,6-1 |
| Challenger Kobe | 2019/11/06 01:30 | Luke Saville v Ken Onishi | 6-2,6-2 |
| ITF M25 Taipei | 2019/07/22 04:00 | Han-Chih Lin v Ken Onishi | 6-7,6-3,10-6 |
| ITF M15 Nonthaburi | 2019/11/26 07:20 | Taisei Ichikawa v Ji Sung Nam | 5-7,2-6 |
| Challenger Kobe | 2019/11/07 02:00 | Yosuke Watanuki v Taisei Ichikawa | 6-2,6-1 |
| Challenger Kobe | 2019/11/06 04:45 | Taisei Ichikawa v Enrique Lopez-Perez | 5-7,6-2,7-6 |
| Challenger Kobe | 2019/11/05 02:45 | Timur Khabibulin v Taisei Ichikawa | 0-6,2-6 |
| ITF M15 Nanchang | 2019/10/04 04:40 | Ye Cong Mo v Taisei Ichikawa | 7-5,4-6,6-3 |
| ITF M15 Nanchang | 2019/10/03 05:00 | Natthasith Kunsuwan v Taisei Ichikawa | 0-6,6-7 |
| ITF M15 Nanchang | 2019/10/01 02:00 | Tianjia Guo v Taisei Ichikawa | 0-6,0-6 |
| ITF M15 Nanchang | 2019/09/27 04:10 | Taisei Ichikawa v Takashi Saito | 4-6,6-2,3-6 |