| ITF Women Osaka Qual | 2018/04/07 01:30 | Ayumi Koshiishi v Akiko Omae | 3-6,2-6 |
| ITF Women Kofu Qual | 2018/03/25 01:00 | Ksenia Lykina v Ayumi Koshiishi | 7-5,6-7,6-3 |
| ITF Women Kofu Qual | 2018/03/24 00:30 | Ayumi Koshiishi v Haruna Arakawa | 7-5,6-4 |
| ITF Women Nishi-Tama | 2018/03/17 04:00 | Kei Kato v Ayumi Koshiishi | 7-5,6-4 |
| ITF Women Toyota Qual | 2018/03/10 01:00 | Ji-Hee Choi v Ayumi Koshiishi | 4-6,6-3,6-2 |
| ITF Women Hong Kong | 2018/01/01 03:35 | Risa Ushijima v Ayumi Koshiishi | 6-1,3-6,7-5 |
| ITF Women Hong Kong | 2017/12/31 02:00 | Ayumi Koshiishi v Pinyi Zuo | 6-1,6-0 |
| ITF Women Hong Kong | 2017/12/30 05:30 | Ayumi Koshiishi v Ashmitha Easwaramurthi | 6-0,6-2 |