Stadium: Court 8 Round: 25 Ground: Hardcourt outdoor
| ITF W25 Daegu | 2019/06/04 01:00 | Ayumi Koshiishi v So-Ra Lee | 7-5,6-2 |
| ITF W25 Luzhou | 2019/05/28 06:15 | Ayumi Koshiishi v Jessica Ho | 3-6,1-6 |
| ITF W25 Luzhou | 2019/05/28 02:00 | Ayumi Koshiishi v WanNing Zhu | 6-0,6-1 |
| ITF W25 Goyang | 2019/05/21 01:00 | Chang Liu v Ayumi Koshiishi | 6-3,4-6,10-8 |
| ITF W25 Goyang | 2019/05/20 01:00 | Hyeran Yun v Ayumi Koshiishi | 4-6,3-6 |
| ITF W25 Changwon | 2019/05/14 01:00 | Ayumi Koshiishi v Dabin Oh | 6-3,3-6,5-10 |
| ITF W25 Changwon | 2019/05/13 01:00 | Ayumi Koshiishi v Si On Park | 6-0,6-1 |
| ITF W60 Fukuoka | 2019/05/06 01:00 | Mai Hontama v Ayumi Koshiishi | 3-6,6-3,10-2 |
| ITF W15 Gimcheon | 2019/06/11 01:00 | Honoka Kobayashi v Dayeon Back | 6-4,0-6,4-10 |
| ITF W15 Gimcheon | 2019/06/10 02:20 | Ah Song v Dayeon Back | 5-7,0-6 |
| ITF W25 Daegu | 2019/06/03 01:00 | Pei-Chi Lee v Dayeon Back | 3-6,7-6,13-11 |
| ITF W25 Goyang | 2019/05/23 03:30 | Jennifer Elie v Dayeon Back | 7-6,6-4 |
| ITF W25 Goyang | 2019/05/21 03:25 | Freya Christie v Dayeon Back | 5-7,2-6 |
| ITF W25 Goyang | 2019/05/20 07:05 | Dayeon Back v Yu Jin Ahn | 6-4,6-0 |
| ITF W25 Changwon | 2019/05/14 01:00 | Yeong Won Jeong v Dayeon Back | 6-4,6-1 |
| ITF W25 Changwon | 2019/05/13 04:10 | Han Gyeol Jeong v Dayeon Back | 0-6,0-6 |