| ITF Women Kurume Qual | 2017/05/15 01:00 | Fujiwara, Rika v Kato, Kei | 6-0,7-6 |
| ITF Women Kurume Qual | 2017/05/14 07:50 | Matsumoto, Hina v Kato, Kei | 3-6,4-6 |
| ITF Women Kurume Qual | 2017/05/14 05:15 | Kajitani, Robu v Kato, Kei | 3-6,6-7 |
| Kofu, Singles Qualifying W-WITF-JPN-02A | 2017/03/27 04:00 | Kato, Kei v Osaka, Mari | 0-6,1-6 |
| Kofu, Singles Qualifying W-WITF-JPN-02A | 2017/03/27 02:30 | So, Kumi v Kato, Kei | 2-6,6-7 |
| Kofu, Singles Qualifying W-WITF-JPN-02A | 2017/03/25 01:00 | Sakata, Kimika v Kato, Kei | 4-6,3-6 |
| Nishi-Tama, Singles W-WITF-JPN-01A | 2017/03/20 01:00 | Kato, Kei v Fujiwara, Rika | 3-6,0-6 |
| Nishi-Tama, Singles W-WITF-JPN-01A | 2017/03/19 01:00 | Takayama, Chihiro v Kato, Kei | 1-6,2-6 |
| ITF Women Karuizawa Qual | 2017/05/20 04:00 | Miyachi, Ran v Pang, Sarah | 6-3,6-4 |
| ITF Women Hamamatsu Qual | 2016/10/15 03:00 | Haruna Arakawa v Miyachi, Ran | 6-0,6-0 |