Stadium: COURT F Round: 26 Ground: Synthetic outdoor
| ITF Women Nonthaburi | 2018/08/05 04:15 | Michika Ozeki v Ayumi Koshiishi | 7-6,5-7,3-6 |
| ITF Women Makinohara | 2018/10/09 00:30 | Ayumi Koshiishi v Kisa Yoshioka | 7-5,6-3 |
| ITF Women Nanao | 2018/08/30 03:00 | Ayumi Koshiishi v Ayano Shimizu | 5-7,3-6 |
| ITF Women Nanao | 2018/08/29 03:30 | Ayumi Koshiishi v Tori Kinard | 7-5,5-7,6-4 |
| ITF Women Nanao | 2018/08/27 05:15 | Ayumi Koshiishi v Yu-Ting Hsieh | 6-0,6-0 |
| ITF Women Nanao | 2018/08/26 05:00 | Ayumi Koshiishi v Ayaka Ozeki | 4-6,6-3,6-3 |
| ITF Women Tsukuba | 2018/08/20 01:00 | Nagi Hanatani v Ayumi Koshiishi | 6-2,7-6 |
| ITF Women Tsukuba | 2018/08/19 00:30 | Ange Oby Kajuru v Ayumi Koshiishi | 1-6,4-6 |
| ITF Women Nonthaburi | 2018/08/11 03:00 | Ayumi Koshiishi v Punnin Kovapitukted | 2-6,2-6 |
| ITF Women Makinohara | 2018/10/10 00:30 | Michika Ozeki v Emily Appleton | 6-3,6-3 |
| ITF Women Kyoto | 2018/09/07 03:30 | Haruna Arakawa v Michika Ozeki | 6-3,6-3 |
| ITF Women Kyoto | 2018/09/06 01:00 | Michika Ozeki v Chie Kezuka | 6-0,6-4 |
| ITF Women Kyoto | 2018/09/05 06:00 | Michika Ozeki v Ayumi Miyamoto | 6-1,6-2 |
| ITF Women Kyoto | 2018/09/04 04:45 | Michika Ozeki v Ayaka Ozeki | 6-2,6-1 |
| ITF Women Nanao | 2018/08/28 03:00 | Himeno Sakatsume v Michika Ozeki | 6-2,6-7,6-4 |
| ITF Women Tsukuba | 2018/08/22 00:30 | Chihiro Muramatsu v Michika Ozeki | 6-1,6-2 |
| ITF Women Tsukuba | 2018/08/20 02:50 | Michika Ozeki v Megumi Nishimoto | 6-3,7-5 |