| ITF W15 Kawaguchi | 06/14 05:35 | 25 | Ayumi Koshiishi v Kisa Yoshioka | 7-6,6-3 | |
| ITF W25 Tokyo | 05/31 01:00 | 25 | Yukina Saigo v Ayumi Koshiishi | 6-4,6-1 | |
| ITF W25 Goyang | 05/22 01:00 | 54 | Ayumi Koshiishi v Yi Tsen Cho | 2-6,0-6 | |
| ITF W25 Goyang | 05/21 01:00 | 54 | Ayumi Koshiishi v Eunji Lee | 6-3,6-3 | |
| ITF W25 Incheon | 05/15 06:40 | 62 | Ayumi Koshiishi v Yujin Ahn | 4-6,3-6 | |
| ITF W25 Incheon | 05/15 02:40 | 62 | Ayumi Koshiishi v Qianhui Tang | 5-7,6-3,10-4 | |
| ITF W25 Osaka | 04/10 01:00 | 62 | Ramu Ueda v Ayumi Koshiishi | Retired | |
| ITF W25 Osaka | 04/09 03:00 | 62 | Kurea Hayasaka v Ayumi Koshiishi | 6-7,4-6 | |
| ITF W25 Kashiwa | 04/03 01:00 | 19 | Katarina Kozarov v Ayumi Koshiishi | 6-0,6-3 | |
| ITF W25 Kofu | 03/29 04:20 | 25 | Ayumi Koshiishi v Eri Hozumi | 4-6,2-6 | |
| ITF W25 Kofu | 03/29 01:00 | 25 | Ayumi Koshiishi v Momoko Kobori | Cancelled | |
| ITF W15 Hinode | 03/26 00:30 | 28 | Natsumi Kawaguchi v Ayumi Koshiishi | 6-1,6-2 | |
| ITF W15 Hinode | 03/24 00:00 | 27 | Yuka Hosoki v Ayumi Koshiishi | 7-5,2-6,0-6 | |
| ITF W15 Hinode | 03/23 02:35 | 26 | Chisa Hosonuma v Ayumi Koshiishi | 2-6,1-6 | |
| ITF W15 Hinode | 03/22 01:00 | 25 | Momoko Nishio v Ayumi Koshiishi | 4-6,6-7 | |
| ITF W15 Kuching | 03/05 01:30 | 29 | Hanyu Guo v Ayumi Koshiishi | 7-5,2-6,1-6 | |
| ITF W15 Kuching | 03/04 01:30 | 28 | Shuo Feng v Ayumi Koshiishi | 0-6,1-6 | |
| ITF W15 Kuching | 03/03 01:30 | 27 | Ayumi Koshiishi v Aoi Ito | 6-1,7-6 | |
| ITF W15 Kuching | 03/02 01:30 | 26 | Ayumi Koshiishi v Kisa Yoshioka | 6-3,6-2 | |
| ITF W15 Kuching | 03/01 09:35 | 25 | Ayumi Koshiishi v Jo-Leen Saw | 6-2,6-0 | |
| ITF W15 Kuala Lumpur | 02/26 01:30 | 29 | Hanyu Guo v Ayumi Koshiishi | 6-4,6-3 | |
| ITF W15 Kuala Lumpur | 02/25 02:00 | 26 | Ayumi Koshiishi v Sara Nayar | Cancelled | |
| ITF W15 Kuala Lumpur | 02/25 01:30 | 28 | Ayumi Koshiishi v Anchisa Chanta | 6-4,7-5 | |
| ITF W15 Kuala Lumpur | 02/24 01:30 | 27 | Ayumi Koshiishi v Riko Sawayanagi | 6-3,7-6 | |
| ITF W15 Kuala Lumpur | 02/23 01:30 | 26 | Ayumi Koshiishi v Meiqi Guo | 6-3,6-1 | |
| ITF W15 Kuala Lumpur | 02/21 01:00 | 25 | Ayumi Koshiishi v Yi Tsen Cho | Retired | |
| ITF W15 Ipoh | 02/18 01:30 | 28 | Lanlana Tararudee v Ayumi Koshiishi | 6-4,7-5 | |
| ITF W15 Ipoh | 02/17 01:30 | 27 | Dabin Kim v Ayumi Koshiishi | 2-6,5-7 | |
| ITF W15 Ipoh | 02/16 03:55 | 26 | Sara Nayar v Ayumi Koshiishi | 4-6,3-6 | |
| ITF W15 Ipoh | 02/15 03:15 | 25 | Shanelle Iaconi v Ayumi Koshiishi | 2-6,2-6 |