Stadium: Court 6 Round: 26 Ground: Synthetic outdoor
| ITF M15 Akishima | 2019/06/12 02:35 | Kosuke Okagaki v Tamaki Yamao | 6-3,6-1 |
| ITF M15 Akishima | 2019/06/11 05:00 | Shunrou Takeshima v Kosuke Okagaki | 2-6,2-6 |
| ITF M15 Akishima | 2019/06/11 00:00 | Kosuke Okagaki v Sam Ryan Ziegann | 6-1,6-0 |
| ITF M15 Antalya | 2019/04/01 07:00 | Dan Alexandru Tomescu v Kosuke Okagaki | 6-3,6-4 |
| ITF M15 Antalya | 2019/03/26 07:00 | Kosuke Okagaki v Wilson Leite | 5-7,7-5,2-6 |
| ITF M15 Antalya | 2019/03/11 07:15 | Kosuke Okagaki v Louroi Martinez | 3-6,6-2,5-10 |
| ITF M15 Antalya | 2019/02/25 14:45 | Mircea-Alexandru Jecan v Kosuke Okagaki | 6-4,6-0 |
| ITF M15 Antalya | 2019/02/25 07:00 | Kosuke Okagaki v Moritz Thiem | 3-6,7-6,10-3 |
| ITF M15 Akishima | 2019/06/12 01:00 | Sho Katayama v Kento Takeuchi | 6-0,6-4 |
| ITF M15 Guam | 2019/06/07 01:35 | Sho Katayama v Hiroyasu Ehara | 3-6,4-6 |
| ITF M15 Guam | 2019/06/06 00:00 | Sho Katayama v Naoki Takeda | 7-6,6-1 |
| ITF M15 Guam | 2019/06/04 01:55 | Sho Katayama v Tomohiro Masabayashi | 6-4,7-6 |
| ITF M25 Matsuyama | 2019/04/10 03:30 | Takuto Niki v Sho Katayama | 6-2,6-3 |
| ITF M15 Kofu | 2019/03/21 04:40 | Takuto Niki v Sho Katayama | 4-6,7-6,6-4 |
| ITF M15 Kofu | 2019/03/20 07:15 | Seita Watanabe v Sho Katayama | 3-6,2-6 |
| ITF M15 Nishi-Tokyo | 2019/03/12 03:20 | Ryota Tanuma v Sho Katayama | 6-4,2-6,10-5 |