| ITF Damen - Osaka - Qualifikation | 04/07 02:30 | 62 | Natsumi Koshino v Dabin Kim | 2-6,4-6 | |
| ITF Damen - Kofu - Qualifikation | 03/26 04:40 | 62 | Natsumi Koshino v Risa Ushijima | 2-6,6-4,2-6 | |
| ITF Damen - Kofu - Qualifikation | 03/25 04:00 | 62 | Jia-Qi Kang v Natsumi Koshino | 6-3,1-6,4-6 | |
| ITF Damen - Nishi-Tama | 03/17 01:00 | 62 | Mei Yamaguchi v Natsumi Koshino | 6-2,6-0 | |
| ITF Damen - Yokohama - Qualifikation | 03/04 04:00 | 54 | Natsumi Koshino v Misa Eguchi | 3-6,2-6 |