Stadium: Court A7 Round: 25 Ground: Synthetic outdoor
| ITF Women Tsukuba | 2018/08/22 00:30 | Shiho Akita v Risa Ushijima | 2-6,2-6 |
| ITF Women Nonthaburi | 2018/08/13 02:00 | Michika Ozeki v Shiho Akita | 6-1,6-2 |
| ITF Women Nonthaburi | 2018/08/06 02:30 | Shiho Akita v Rutuja Bhosale | 6-4,1-6,6-2 |
| ITF Women Granby | 2018/07/24 22:25 | Astra Sharma v Shiho Akita | 7-6,6-1 |
| ITF Women Gatineau | 2018/07/16 14:00 | Sophie Chang v Shiho Akita | 6-4,5-7,6-1 |
| ITF Women Honolulu | 2018/07/10 23:20 | Usue Maitane Arconada v Shiho Akita | 6-0,1-6,7-6 |
| ITF Women Daegu | 2018/06/20 01:00 | Shiho Akita v Hanna Chang | 0-6,5-7 |
| ITF Women Karuizawa | 2018/05/22 01:00 | Chihiro Muramatsu v Shiho Akita | 6-2,6-4 |
| ITF Women Tsukuba | 2018/08/21 00:30 | Riko Sawayanagi v Momoko Kobori | 4-6,3-6 |
| ITF Women Toyota Qual | 2018/03/11 03:30 | Riko Sawayanagi v Mayu Iwai | 6-0,1-6,2-6 |
| ITF Women Toyota Qual | 2018/03/10 01:00 | Riko Sawayanagi v Himari Sato | 7-5,6-0 |
| ITF Women Mildura | 2018/03/06 01:05 | Maddison Inglis v Riko Sawayanagi | 6-0,6-2 |
| ITF Women Perth Qual | 2018/02/19 05:05 | Riko Sawayanagi v Lulu Sun | 2-6,3-6 |
| ITF Women Perth Qual | 2018/02/18 03:00 | Riko Sawayanagi v Ramu Ueda | 6-3,7-5 |
| ITF Women Perth | 2018/02/15 02:00 | Riko Sawayanagi v Mai Minokoshi | 1-6,1-6 |
| ITF Women Perth Qual | 2018/02/12 04:35 | Riko Sawayanagi v Maryna Chernyshova | 6-4,6-2 |