| 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 |
| Finnish Open WD | 2019/04/05 14:20 | Iwanaga/Nakanishi v Ercetin/Inci | W | 2-0 |
| Dutch Open WD | 2019/10/10 15:10 | Nistad C / Sjoo M v Piek S / Seinen C | W | 0-2 |
| Dutch Open WD | 2019/10/09 14:35 | Pope I / Radovska M v Piek S / Seinen C | W | 0-2 |
| Korea Open 2019, WD | 2019/09/25 07:20 | Honderich R / Tsai K v Piek S / Seinen C | L | 2-0 |
| China Open 2018, Women Doubles | 2019/09/19 04:30 | Piek S / Seinen C v Fukushima/Hirota | L | 0-2 |
| China Open 2018, Women Doubles | 2019/09/18 11:00 | Piek S / Seinen C v Delrue D / Palermo L | W | 2-0 |
| World Championships WD | 2019/08/21 09:00 | Matsumoto/Nagahara v Piek S / Seinen C | L | 2-0 |
| World Championships WD | 2019/08/19 08:00 | Piek S / Seinen C v Yeung M N / Ng T Y | W | 2-0 |
| Japan Open WD | 2019/07/23 06:10 | Piek S / Seinen C v Polii G / Rahayu A | L | 0-2 |