| ITF W60 Saint-Malo | 09/17 13:25 | 54 | Mari Osaka v Lucie Wargnier | 4-6,2-6 | |
| ITF W25 St. Poelten | 09/10 10:05 | 25 | [305] Mari Osaka v Caroline Werner [367] | 2-6,1-6 | |
| ITF W60 Montreux | 09/06 14:50 | 27 | [500] Alice Rame v Mari Osaka [305] | 6-0,6-4 | |
| ITF W60 Montreux | 09/05 10:30 | 26 | [305] Mari Osaka v Mandy Minella [142] | 6-1,3-6,6-4 | |
| ITF W60 Montreux | 09/04 08:00 | 25 | Fiona Ganz v Mari Osaka | 4-6,2-6 | |
| ITF W25 Guayaquil | 08/21 15:00 | 25 | Mari Osaka v Camila Romero | 6-2,5-7,4-6 | |
| ITF W25 Guayaquil | 08/16 18:15 | 27 | [344] Gabriela Talaba v Mari Osaka [315] | 6-4,6-3 | |
| ITF W25 Guayaquil | 08/15 15:00 | 26 | [463] Maria Jose Portillo Ramirez v Mari Osaka [315] | 3-6,2-6 | |
| ITF W25 Guayaquil | 08/14 15:00 | 25 | Mell E R Gonzalez v Mari Osaka | 6-7,3-6 | |
| ITF W25 Oporto | 07/27 12:00 | 28 | [313] Mari Osaka v Myrtille Georges [267] | 6-7,5-7 | |
| ITF W25 Oporto | 07/26 12:05 | 27 | [190] Pemra Ozgen v Mari Osaka [313] | 4-6,1-6 | |
| ITF W25 Oporto | 07/25 19:55 | 26 | Shrivalli R Bhamidipaty v Mari Osaka | 3-6,2-6 | |
| ITF W25 Oporto | 07/24 14:05 | 25 | [177] Sarah Beth Grey v Mari Osaka [313] | 5-7,5-7 | |
| ITF W25 Palmela | 07/16 10:15 | 25 | [312] Mari Osaka v Eden Silva [439] | 6-4,1-6,4-6 | |
| ITF W25 Corroios-Seixal | 07/04 12:45 | 26 | [300] Mari Osaka v Paige Hourigan [426] | 6-7,4-6 | |
| ITF W25 Corroios-Seixal | 07/03 16:55 | 25 | Mari Osaka v Laura Schaeder | 6-0,6-4 | |
| ITF W25 Madrid | 06/22 09:00 | 28 | [314] Mari Osaka v Eva Guerrero Alvarez [310] | 6-3,5-7,4-6 | |
| ITF W25 Madrid | 06/21 08:30 | 27 | [427] Ana Sofia Sanchez v Mari Osaka [314] | 6-7,3-6 | |
| ITF W25 Madrid | 06/20 11:15 | 26 | Julia Payola v Mari Osaka | 2-6,1-6 | |
| ITF W25 Madrid | 06/19 07:30 | 25 | Polina Monova v Mari Osaka | 6-4,3-6,5-7 | |
| ITF W25 Daegu | 06/08 04:45 | 28 | [189] Na-Lae Han v Mari Osaka [359] | 6-4,6-4 | |
| ITF W25 Daegu | 06/08 01:00 | 27 | [484] Dabin Kim v Mari Osaka [359] | 4-6,1-6 | |
| ITF W25 Daegu | 06/06 03:30 | 26 | Eunhye Lee v Mari Osaka | 3-6,3-6 | |
| ITF W25 Daegu | 06/04 04:00 | 25 | [426] Hanna Chang v Mari Osaka [359] | Retired | |
| ITF W25 Nonthaburi | 05/30 07:15 | 26 | [434] Ipek Soylu v Mari Osaka [359] | 6-3,7-6 | |
| ITF W25 Nonthaburi | 05/29 06:55 | 25 | [491] Maryna Chernyshova v Mari Osaka [359] | 2-6,2-6 | |
| ITF W25 Nonthaburi | 05/24 07:30 | 27 | [340] Mari Osaka v Maddison Inglis [271] | 4-6,2-6 | |
| ITF W25 Nonthaburi | 05/23 05:25 | 26 | Mari Osaka v Magali Kempen | 6-2,7-5 | |
| ITF W25 Nonthaburi | 05/21 11:20 | 25 | Mari Osaka v Punnin Kovapitukted | 6-3,6-3 | |
| ITF W100 Bonita Springs | 05/06 16:45 | 45 | [379] Gabriela Talaba v Mari Osaka [336] | Retired |