| Dutch Open WD | 2019/10/11 16:50 | Iwanaga/Nakanishi v Piek S / Seinen C | W | 2-0 |
| Dutch Open WD | 2019/10/10 16:45 | Boeje A / Poulsen M v Iwanaga/Nakanishi | W | 0-2 |
| Dutch Open WD | 2019/10/09 13:15 | Iwanaga/Nakanishi v Birch C / Smith L | W | 2-0 |
| Akita Masters 2019, WD | 2019/08/16 03:20 | Iwanaga/Nakanishi v Sakuram. / Takah. | L | 0-2 |
| Akita Masters 2019, WD | 2019/08/15 03:55 | Kawashima M / Saito N v Iwanaga/Nakanishi | W | 0-2 |
| Akita Masters 2019, WD | 2019/08/14 06:00 | Iwanaga/Nakanishi v Istarani N K M / Kusumah T O | W | 2-0 |
| Finnish Open WD | 2019/04/06 14:30 | Honda E / Shimizu N v Iwanaga/Nakanishi | L | 2-1 |
| Finnish Open WD | 2019/04/05 19:00 | Pai Y P / Wu T J v Iwanaga/Nakanishi | W | 0-2 |
| Dutch Open WD | 2019/10/11 16:30 | Hobara S / Sone N v Efler L / Herttrich I | W | 1-2 |
| Dutch Open WD | 2019/10/09 17:50 | Fankhauser N / Tabeling I v Efler L / Herttrich I | W | 0-2 |
| China Open 2018, Women Doubles | 2019/09/17 02:00 | Efler L / Herttrich I v Kim/Kong | L | 0-2 |
| Vietnam Open WD | 2019/09/13 12:40 | Efler L / Herttrich I v Huang J / Zhang S X | L | 1-2 |
| Vietnam Open WD | 2019/09/13 11:20 | Efler L / Herttrich I v Huang J / Zhang S X | L | 1-2 |
| Vietnam Open WD | 2019/09/12 08:00 | Efler L / Herttrich I v Saito N / Shinoya N | W | 2-0 |
| Vietnam Open WD | 2019/09/11 12:30 | Efler L / Herttrich I v Chen X / Zhou C | W | 2-1 |
| World Championships WD | 2019/08/21 08:40 | Efler L / Herttrich I v Li/Zheng | L | 0-2 |