Stadium: Court D Round: 54 Ground: Hardcourt outdoor
| ITF W60 Fukuoka | 2019/05/06 01:00 | Mai Hontama v Ayumi Koshiishi | 3-6,6-3,10-2 |
| ITF W25 Hong Kong | 2019/04/08 02:00 | Ayumi Koshiishi v Mihika Yadav | 6-3,2-6,4-10 |
| ITF W25 Jackson | 2019/04/03 16:40 | Ayumi Koshiishi v Ann Li | 1-6,2-6 |
| ITF W25 Jackson | 2019/04/02 15:00 | Ayumi Koshiishi v Alesya Yakubovich | 6-3,6-2 |
| ITF W25 Canberra | 2019/03/25 00:00 | Ayumi Koshiishi v Yuuki Tanaka | 3-6,1-6 |
| ITF W15 Xiamen | 2019/03/22 03:35 | Ayumi Koshiishi v Eudice Chong | 2-6,3-6 |
| ITF W15 Xiamen | 2019/03/20 02:00 | Ayumi Koshiishi v Ashmitha Easwaramurthi | 6-0,6-1 |
| ITF W15 Shymkent | 2019/02/21 08:20 | Ayumi Koshiishi v Anastasia Zakharova | 4-6,4-6 |