| Akita Masters 2019, MS | 2019/08/15 02:15 | Sakai, Kazumasa v Igarashi, Yu | W | 1-2 |
| Akita Masters 2019, MS | 2019/08/14 03:20 | Igarashi, Yu v Choi, Ji Hoon | W | 2-0 |
| US Open 2019, MS | 2019/07/11 01:55 | Igarashi, Yu v H.S. Prannoy | L | 1-2 |
| Canada Open | 2019/07/03 17:10 | Igarashi, Yu v Chun-Yi Lin | L | 0-2 |
| Australian Open Qual | 2019/06/04 00:45 | Igarashi, Yu v Saensomboonsuk, Tanongsak | L | 1-2 |
| New Zealand Open 2019, MS | 2019/05/01 04:40 | Igarashi, Yu v Kanta Tsuneyama | L | 0-2 |
| New Zealand Open 2019, MS | 2019/04/30 20:00 | Igarashi, Yu v Kanta Tsuneyama | L | 0-2 |
| Singapore Open 2019, MS, Qualification | 2019/04/09 05:07 | Parupalli, Kashyap v Igarashi, Yu | L | 2-1 |
| Akita Masters 2019, MS | 2019/08/15 05:25 | Koki Watanabe v Thongnuam, Pannawit | W | 2-0 |
| Akita Masters 2019, MS | 2019/08/14 02:10 | Koki Watanabe v Koga, Minoru | W | 2-0 |
| US Open 2019, MS | 2019/07/11 22:00 | Lee, Dong Keun v Koki Watanabe | L | 2-1 |
| US Open 2019, MS | 2019/07/10 22:10 | Svendsen, Victor v Koki Watanabe | W | 0-2 |
| Canada Open | 2019/07/06 21:30 | Koki Watanabe v Li, S. F. | L | 1-2 |
| Canada Open | 2019/07/05 22:00 | Ouseph, Rajiv v Koki Watanabe | W | 0-2 |
| Canada Open | 2019/07/04 21:55 | Lei, L. X. v Koki Watanabe | W | 1-2 |
| Canada Open | 2019/07/03 19:00 | Koki Watanabe v H.S. Prannoy | W | 2-0 |