Stadium: Court 13 Round: 25 Ground: Synthetic outdoor
| ITF Women Kurume Qual | 2018/05/13 09:50 | Mei Yamaguchi v Kotomi Takahata | 6-3,3-6,4-6 |
| ITF Women Fukuoka | 2018/05/09 04:20 | Mei Yamaguchi v Arina Rodionova | 0-6,5-7 |
| ITF Women Gifu | 2018/05/01 01:00 | Mei Yamaguchi v Momoko Kobori | 6-4,3-6,3-6 |
| ITF Women Gifu Qual | 2018/04/30 03:00 | Makoto Ninomiya v Mei Yamaguchi | 6-4,4-6,4-6 |
| ITF Women Gifu Qual | 2018/04/29 04:20 | Mei Yamaguchi v Yuki Kristina Chiang | 6-1,6-2 |
| ITF Women Osaka Qual | 2018/04/08 03:30 | Ya-Hsuan Lee v Mei Yamaguchi | 3-6,6-1,6-4 |
| ITF Women Kofu Qual | 2018/03/25 01:00 | Mei Yamaguchi v Kyoka Okamura | 6-1,3-6,1-6 |
| ITF Women Kofu Qual | 2018/03/24 00:30 | Mei Yamaguchi v Suzuho Oshino | 6-1,7-6 |
| ITF Women Kurume | 2018/05/15 02:40 | Olivia Tjandramulia v Risa Ushijima | 6-2,2-6,6-4 |
| ITF Women Osaka | 2018/04/11 02:45 | Risa Ushijima v En Shuo Liang | 1-6,4-6 |
| ITF Women Osaka Qual | 2018/04/09 01:00 | Ange Oby Kajuru v Risa Ushijima | 3-6,2-6 |
| ITF Women Osaka Qual | 2018/04/08 02:00 | Mayuka Aikawa v Risa Ushijima | 4-6,1-6 |
| ITF Women Kashiwa Qual | 2018/04/01 00:30 | Karman Kaur Thandi v Risa Ushijima | 6-3,6-1 |
| ITF Women Kofu | 2018/03/28 01:00 | Karman Kaur Thandi v Risa Ushijima | 6-3,6-3 |
| ITF Women Kofu Qual | 2018/03/26 04:40 | Natsumi Koshino v Risa Ushijima | 2-6,6-4,2-6 |
| ITF Women Kofu Qual | 2018/03/25 04:00 | Suzuka Furukawa v Risa Ushijima | 3-6,0-6 |