| Open de France - Doubles Femmes | 10/26 13:45 | 4 | Iwanaga/Nakanishi v Kititharakul/Prajongjai | L | 0-2 | |
| Open de France - Doubles Femmes | 10/25 10:45 | 5 | Hsin Lee/Teng v Iwanaga/Nakanishi | W | 0-2 | |
| Denmark Open WD | 10/21 09:15 | 2 | Chen/Fan Jia v Iwanaga/Nakanishi | L | 2-0 | |
| Denmark Open WD | 10/20 12:05 | 3 | Iwanaga/Nakanishi v Zhang/Zheng | W | 2-1 | |
| Denmark Open WD | 10/19 12:30 | 4 | Liu/Tan v Iwanaga/Nakanishi | W | 0-2 | |
| Denmark Open WD | 10/18 14:45 | 5 | Iwanaga/Nakanishi v Fruergaard/Thygesen | W | 2-0 | |
| Arctic Open WD | 10/14 16:55 | 2 | Iwanaga/Nakanishi v Kititharakul/Prajongjai | L | 0-2 | |
| Arctic Open WD | 10/13 16:45 | 3 | Iwanaga/Nakanishi v Hsin Lee/Teng | W | 2-0 | |
| Arctic Open WD | 10/12 11:35 | 4 | Efler/Lohau v Iwanaga/Nakanishi | W | 0-2 | |
| Arctic Open WD | 10/11 14:00 | 5 | Kruus/Uprus v Iwanaga/Nakanishi | W | 0-2 | |
| Hong Kong Open 2019, WD | 09/14 01:45 | 4 | Kititharakul/Prajongjai v Iwanaga/Nakanishi | L | 2-1 | |
| Hong Kong Open 2019, WD | 09/13 01:00 | 5 | Iwanaga/Nakanishi v Cao Hok/Lam | W | 2-0 | |
| China Open 2018, Women Doubles | 09/05 06:05 | 5 | Iwanaga/Nakanishi v Yeung/Yeung | L | 1-2 | |
| World Championships WD | 08/24 10:15 | 4 | Matsuyama/Shida v Iwanaga/Nakanishi | L | 2-0 | |
| World Championships WD | 08/23 09:20 | 5 | Iwanaga/Nakanishi v Fruergaard/Thygesen | W | 2-1 | |
| Australian Open WD | 08/04 02:15 | 3 | Miyaura/Sakuramoto v Iwanaga/Nakanishi | L | 2-0 | |
| Australian Open WD | 08/03 10:10 | 4 | Iwanaga/Nakanishi v Matsuyama/Shida | W | 2-0 | |
| Australian Open WD | 08/01 06:45 | 5 | Liu/Wang v Iwanaga/Nakanishi | W | 0-2 | |
| Japan Open WD | 07/26 01:00 | 5 | Iwanaga/Nakanishi v Kim/Kong | L | 0-2 | |
| Korea Open WD | 07/21 04:55 | 3 | Chen/Fan Jia v Iwanaga/Nakanishi | L | 2-1 | |
| Korea Open WD | 07/20 00:10 | 4 | Iwanaga/Nakanishi v Liu/Wang | W | 2-0 | |
| Korea Open WD | 07/18 07:00 | 5 | Shida/Matsuyama v Iwanaga/Nakanishi | W | 0-2 | |
| Canada Open WD | 07/06 23:20 | 4 | Aimsaard/Aimsaard v Iwanaga/Nakanishi | L | 2-0 | |
| Canada Open WD | 07/05 03:05 | 5 | Nakanishi/Iwanaga v Xu/Yu | W | 2-0 | |
| Indonesia Open WD | 06/15 07:35 | 4 | Baek/Lee v Iwanaga/Nakanishi | L | 2-1 | |
| Indonesia Open WD | 06/13 04:20 | 5 | Iwanaga/Nakanishi v Jolly/Pullela | W | 2-1 | |
| Singapore Open WD | 06/09 08:00 | 3 | Iwanaga/Nakanishi v Zhang/Zheng | L | 1-2 | |
| Singapore Open WD | 06/08 13:00 | 4 | Iwanaga/Nakanishi v Rahayu/Ramadhanti | W | 2-1 | |
| Singapore Open WD | 06/07 03:05 | 5 | Tan P K L / Thinaah M v Iwanaga/Nakanishi | - | away | |
| Open de Thaïlande - Doubles Femmes | 06/02 06:50 | 3 | Aimsaard/Aimsaard v Iwanaga/Nakanishi | L | 2-0 |