Stadium: Court 10 Round: 44 Ground: Hardcourt outdoor
| ITF W15 Hua Hin | 2019/10/10 03:00 | Patcharin Cheapchandej v Ayumi Koshiishi | 6-1,6-3 |
| ITF W15 Hua Hin | 2019/10/09 03:00 | Ayumi Koshiishi v Mananchaya Sawangkaew | 6-2,6-3 |
| ITF W25 Kjóto | 2019/09/05 05:30 | Ayumi Koshiishi v Michika Ozeki | 0-6,3-6 |
| ITF W25 Kjóto | 2019/09/04 04:25 | Miharu Imanishi v Ayumi Koshiishi | 3-6,4-6 |
| ITF W25 Kjóto | 2019/09/02 04:00 | Ayumi Koshiishi v Utaka Kishigami | 7-5,7-6 |
| ITF W25 Kjóto | 2019/09/02 00:00 | Ayumi Koshiishi v Hx Izabella Tan | 6-0,6-1 |
| ITF W25 Nanao | 2019/08/27 01:00 | Ayumi Koshiishi v Anri Nagata | 4-6,0-6 |
| ITF W25 Tsukuba | 2019/08/19 00:30 | Yui Chikaraishi v Ayumi Koshiishi | 2-6,6-2,10-7 |