| 1. Round | 03/04/2021 | Yokohama FC [U18] | - | Kashiwa Reysol [U18] | 1:0 | ||||
| 2. Round | 10/04/2021 | Kashiwa Reysol [U18] | - | Yokohama F. Marinos [U18] | 2:3 | ||||
| 3. Round | 18/04/2021 | Omiya Ardija [U18] | - | Kashiwa Reysol [U18] | 2:3 | ||||
| 4. Round | 25/04/2021 | Kashiwa Reysol [U18] | - | Ryutsu Keizai University [U18] | 1:1 | ||||
| 5. Round | 01/05/2021 | Shimizu S-Pulse [U18] | - | Kashiwa Reysol [U18] | 4:0 | ||||
| 14. Round | 10/10/2021 | Kashiwa Reysol [U18] | - | Shimizu S-Pulse [U18] | 2:2 | ||||
| 15. Round | 17/10/2021 | Urawa Red Diamonds [U18] | - | Kashiwa Reysol [U18] | 1:1 | ||||
| 7. Round | 24/10/2021 | FC Tokyo [U18] | - | Kashiwa Reysol [U18] | 0:1 | ||||
| 10. Round | 31/10/2021 | Kashiwa Reysol [U18] | - | Yokohama FC [U18] | 2:0 | ||||
| 11. Round | 06/11/2021 | Yokohama F. Marinos [U18] | - | Kashiwa Reysol [U18] | 3:2 | ||||
| 12. Round | 13/11/2021 | Kashiwa Reysol [U18] | - | Omiya Ardija [U18] | 5:0 | ||||
| 17. Round | 28/11/2021 | Kashiwa Reysol [U18] | - | Aomori Yamada High School [U18] | 1:4 | ||||
| 18. Round | 05/12/2021 | Ichiritsu Funabashi High School [U18] | - | Kashiwa Reysol [U18] | 3:2 |
Japan