Stadium: Court 7 Round: 54 Ground: Hardcourt outdoor
| Luzhou, Simples W-ITF-CHN-09A | 2019/05/28 06:15 | Ayumi Koshiishi v Ho, Jessica | 3-6,1-6 |
| Luzhou, Simples W-ITF-CHN-09A | 2019/05/28 02:00 | Ayumi Koshiishi v Zhu, Wanning | 6-0,6-1 |
| ITF W25 Goyang | 2019/05/21 01:00 | Liu, Chang v Ayumi Koshiishi | 6-3,4-6,10-8 |
| ITF W25 Goyang | 2019/05/20 01:00 | Yun, Hyeran v Ayumi Koshiishi | 4-6,3-6 |
| ITF W25 Changwon | 2019/05/14 01:00 | Ayumi Koshiishi v Oh, Soo Bin | 6-3,3-6,5-10 |
| ITF W25 Changwon | 2019/05/13 01:00 | Ayumi Koshiishi v Park, SI On | 6-0,6-1 |
| Fukuoka, Singles W-ITF-JPN-10A | 2019/05/06 01:00 | Mai Hontama v Ayumi Koshiishi | 3-6,6-3,10-2 |
| Hong Kong, Simples W-ITF-HKG-01B | 2019/04/08 02:00 | Ayumi Koshiishi v Yadav, Mihika | 6-3,2-6,4-10 |
| ITF W25 Incheon | 2019/05/28 01:00 | Chanel Simmonds v Jeong, Yeong Won | 6-2,6-3 |
| ITF W25 Incheon | 2019/05/27 05:25 | Yun, Hyeran v Jeong, Yeong Won | 6-7,3-6 |
| ITF W25 Goyang | 2019/05/23 02:00 | Lumsden, Maia v Jeong, Yeong Won | 6-1,6-1 |
| ITF W25 Goyang | 2019/05/22 01:00 | Hanna Chang v Jeong, Yeong Won | 3-6,6-3,4-6 |
| ITF W25 Changwon | 2019/05/15 01:00 | Ya-Hsuan Lee v Jeong, Yeong Won | 6-0,6-2 |
| ITF W25 Changwon | 2019/05/14 01:00 | Jeong, Yeong Won v Dayeon Back | 6-4,6-1 |
| ITF W25 Changwon | 2019/05/13 04:15 | Jeong, Yeong Won v Chun, Su Yeon | 6-0,6-2 |
| Antalya, Singles Qualifying W-WITF-TUR-08A | 2018/12/14 10:05 | Jeong, Yeong Won v Monica Robinson | 6-3,6-2 |