Stadium: Court 6 Round: 27
| Yokohama, Singles Qualifying W-WITF-JPN-01B | 2018/03/04 07:00 | Okuno, Ayaka v Ya-Hsuan Lee | 4-6,4-6 |
| ITF Women Sangju | 2018/06/07 03:05 | Okuno, Ayaka v Subin Park | 7-6,6-4 |
| ITF Women Sangju | 2018/06/06 01:00 | Okuno, Ayaka v Yea, Hyojung | 6-3,6-3 |
| Karuizawa, Singles W-WITF-JPN-10A | 2018/05/24 03:55 | Okuno, Ayaka v Myers, Abbie | 2-6,3-6 |
| Karuizawa, Singles W-WITF-JPN-10A | 2018/05/23 01:00 | Nefedova, Anastasia Evgenyevna v Okuno, Ayaka | 7-6,3-6,4-6 |
| ITF Women Kurume Qual | 2018/05/13 00:30 | Hondo, Sakura v Okuno, Ayaka | 6-7,6-4,7-6 |
| ITF Women Fukuoka Qual | 2018/05/06 07:05 | Inoue, Akari v Okuno, Ayaka | 6-1,6-4 |
| ITF Women Gifu Qual | 2018/04/29 03:10 | Mai Hontama v Okuno, Ayaka | 5-7,7-6,6-2 |
| Quanzhou, Qualifications Simples W-WITF-CHN-04B | 2018/04/21 05:45 | Gai, AO v Okuno, Ayaka | 6-3,6-4 |
| ITF Women Sangju | 2018/06/07 01:00 | Wang, Dan Ni v Ya-Hsuan Lee | 1-6,2-6 |
| ITF Women Sangju | 2018/06/06 04:05 | Dayeon Back v Ya-Hsuan Lee | 1-6,0-6 |
| ITF Women Changwon | 2018/05/27 02:00 | Flink, Varvara v Ya-Hsuan Lee | 6-0,3-6,0-6 |
| ITF Women Changwon | 2018/05/26 01:00 | Ya-Hsuan Lee v Ulrikke Eikeri | 6-1,6-2 |
| ITF Women Changwon | 2018/05/25 01:00 | Lee, So-Ra v Ya-Hsuan Lee | 4-6,4-6 |
| ITF Women Changwon | 2018/05/24 02:40 | Ayumi Koshiishi v Ya-Hsuan Lee | 4-6,3-6 |
| ITF Women Changwon | 2018/05/23 05:05 | Ya-Hsuan Lee v Na-Lae Han | 6-4,6-3 |
| ITF Women Incheon | 2018/05/17 01:30 | Na-Lae Han v Ya-Hsuan Lee | 4-6,6-3,7-6 |