Stadium: Court 2 Round: 25 Ground: Hardcourt outdoor
| WTA Tokyo WD | 2018/09/22 07:00 | Hlavackova/Strycova v Kato/Ninomiya | 4-6,4-6 |
| WTA Tokyo WD | 2018/09/21 05:00 | Kato/Ninomiya v Dabrowski/Wu | 7-6,6-0 |
| WTA Tokyo WD | 2018/09/20 04:15 | Kato/Ninomiya v Kichenok/Srebotnik | 6-4,2-6,10-7 |
| WTA Tokyo WD | 2018/09/19 04:45 | Kobori/Shimizu v Kato/Ninomiya | 4-6,3-6 |
| WTA Hiroshima WD | 2018/09/16 05:15 | Kato/Ninomiya v Hozumi/Zhang | 2-6,4-6 |
| WTA Hiroshima WD | 2018/09/14 06:45 | Kato/Ninomiya v Savinykh/Sorribes Tormo | 7-6,6-4 |
| WTA Hiroshima WD | 2018/09/13 07:55 | Kato/Ninomiya v Diyas/Zheng | 5-7,6-2,10-5 |
| WTA Hiroshima WD | 2018/09/13 04:55 | Kato/Ninomiya v Perez/Rodionova | 6-7,6-3,10-6 |