Head to Head
| Qatar Open Women | 2018/08/23 14:00 | Mizuki Oikawa v Koki Niwa | L | 4-1 |
Home History
| Olympics 2020 - Team Men | 2021/08/06 03:00 | Youngsik Jeoung v Koki Niwa | L | 3-0 |
| Olympics 2020 - Team Men | 2021/08/04 13:30 | Koki Niwa v Dimitrij Ovtcharov | L | 0-3 |
| Olympics 2020 - Team Men | 2021/08/03 02:30 | Koki Niwa v Mattias Falck | W | 3-0 |
| Olympics 2020 - Men | 2021/07/27 12:30 | Koki Niwa v Dimitrij Ovtcharov | L | 1-4 |
| Olympics 2020 - Men | 2021/07/27 06:30 | Koki Niwa v Yang Wang | W | 4-0 |
| WTT Star Contender Doha | 2021/03/09 12:35 | Koki Niwa v Gustavo Tsuboi | L | 0-3 |
| Japan T League | 2020/12/24 10:30 | Koki Niwa v Kazuhiro Yoshimura | L | 0-3 |
| Japan T League | 2020/12/23 11:35 | Jun Mizutani v Koki Niwa | L | 3-2 |
Away History
| WTT Star Contender Doha | 2021/03/07 09:20 | Mizuki Oikawa v Paul Drinkhall | L | 0-3 |
| WTT Star Contender Doha | 2021/03/06 16:30 | Mizuki Oikawa v Anthony Amalraj | W | 3-1 |
| Japan T League | 2021/02/26 08:10 | Mizuki Oikawa v Maharu Yoshimura | L | 2-3 |
| Japan T League | 2021/02/21 03:30 | Mizuki Oikawa v Ryoichi Yoshiyama | W | 3-0 |
| Japan T League | 2021/02/09 09:00 | Mizuki Oikawa v Kenta Matsudaira | L | 0-3 |
| Japan T League | 2021/01/30 05:00 | Maharu Yoshimura v Mizuki Oikawa | L | 3-0 |
| Japan T League | 2020/12/23 11:10 | Mizuki Oikawa v Masaki Yoshida | W | 3-0 |
| Japan T League | 2020/12/17 04:00 | Mizuki Oikawa v Shunsuke Togami | W | 3-2 |