Additions
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 08/2021 |  | Kosuke Kinoshita | FW |  | Stabæk IF | Stabæk |
| 08/2021 | | Yuichi Hirano | MF |  | Mito HollyHock | Mito HollyHock |
| 07/2021 |  | Alexander Scholz | DF |  | FC Midtjylland | Midtjylland |
| 07/2021 | | Hiroki Sakai | DF |  | Olympique de Marseille | Marseille |
| 07/2021 | | Ataru Esaka | MF |  | Kashiwa Reysol | Kashiwa Reysol |
| 04/2021 | | Kota Kudo | DF |  | Urawa Red Diamonds U18 | U18 |
| 04/2021 | | Kasper Junker | FW |  | FK Bodø/Glimt | Bodø/Glimt |
| 02/2021 | | Maiki Hayashi | AS-CO |  | Nara Club | Nara Club |
| 01/2021 | | Hitoshi Shiota | GK |  | Tochigi SC | Tochigi SC |
| 01/2021 | | Takahiro Akimoto | MF | | Tochigi SC | Tochigi SC |
| 01/2021 | | Daiki Kaneko | MF |  | Shonan Bellmare | Shonan Bellmare |
| 01/2021 | | Tatsuya Tanaka | MF |  | Oita Trinita | Oita Trinita |
| 01/2021 | | Yudai Fujiwara | DF |  | Aomori Yamada High School U18 | U18 |
| 01/2021 | | Ryuya Fukushima | DF | |||
| 01/2021 | | Daigo Nishi | DF |  | Vissel Kobe | Vissel Kobe |
| 01/2021 | | Haruki Izawa | MF |  | Kagoshima United | Kagoshima |
| 01/2021 | | Yoshio Koizumi | MF |  | FC Ryūkyū | FC Ryūkyū |
| 01/2021 | | Tomoaki Okubo | FW |  | Chuo University | Chuo University |
| 01/2021 |  | Ricardo Rodríguez | MA |  | Tokushima Vortis | Tokushima Vortis |
Departures
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 07/2021 | | Hidetoshi Takeda | MF | | FC Ryūkyū | FC Ryūkyū |
| 07/2021 | | Kenyu Sugimoto | FW |  | Yokohama F. Marinos | Marinos |
| 07/2021 | | Yuki Muto | FW | | Kashiwa Reysol | Kashiwa Reysol |
| 07/2021 | | Ryotaro Ito | MF | | Mito HollyHock | Mito HollyHock |
| 07/2021 | | Yudai Fujiwara | DF |  | SC Sagamihara | SC Sagamihara |
| 03/2021 | | Yosuke Kashiwagi | MF |  | FC Gifu | FC Gifu |
| 02/2021 |  | Leonardo | FW |  | Shandong Taishan | Shandong Tai. |
| 02/2021 | | Haruki Fukushima | GK |  | Kyoto Sanga FC | Kyoto |
| 02/2021 | | Ryo Ishii | GK |  | Renofa Yamaguchi | Renofa Yamaguchi |
| 02/2021 | | Haruki Izawa | MF |  | Giravanz Kitakyushu | Giravanz Kitakyushu |
| 01/2021 | | Daiki Hashioka | DF |  | Sint-Truidense VV | STVV |
| 01/2021 | | Daisuke Suzuki | DF |  | JEF United Chiba | JEF United |
| 01/2021 | | Takuya Aoki | MF |  | FC Tokyo | FC Tokyo |
| 01/2021 | | Kazuki Nagasawa | MF |  | Nagoya Grampus | Nagoya Grampus |
| 01/2021 |  | Quenten Martinus | FW |  | Vegalta Sendai | Vegalta Sendai |
| 01/2021 | | Kosuke Taketomi | FW | | Kyoto Sanga FC | Kyoto |
| 01/2021 | | Katsuya Iwatake | DF |  | Yokohama FC | Yokohama FC |
| 01/2021 | | Ewerton | MF |  | FC Porto | FC Porto |
| 01/2021 | | Yuta Miyamoto | MF |  | Ryutsu Keizai University | Ryutsu Keizai University |