Stadium: Indoor 7 Round: 62 Ground: Synthetic outdoor
| ITF Women Hamamatsu | 2018/10/14 04:30 | Ayumi Koshiishi v Mayuka Aikawa | 6-3,6-2 |
| ITF Women Hamamatsu | 2018/10/14 00:00 | Ayumi Koshiishi v Yui Chikaraishi | 7-6,6-2 |
| ITF Women Makinohara | 2018/10/11 00:30 | Ayumi Koshiishi v Michika Ozeki | 2-6,0-6 |
| 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 Hamamatsu | 2018/10/14 04:00 | Karen Tsutsumi v Aoiko Goto | 4-6,7-5,6-1 |
| ITF Women Hamamatsu | 2018/10/14 00:00 | Karen Tsutsumi v Marie Shindo | 6-3,7-6 |