Japanese Box Office For September 2021
| Rank | Release | Gross | Max Th | Opening | % of Total | Open Th | Open | Close | Distributor |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Masquerade Night | $31,775,836 | - | $4,874,476 | 15.3% | - | Sep 17 | - | Toho |
| 2 | Shang-Chi and the Legend of the Ten Rings | $8,763,893 | - | $2,746,264 | 31.3% | - | Sep 3 | - | Walt Disney Studios Motion Pictures |
| 3 | Gekijouban Free! the Final Stroke - Part 1 | $4,755,182 | - | $789,681 | 16.6% | - | Sep 17 | - | Shochiku |
| 4 | The Woman of S.R.I.: The Movie | $3,450,057 | - | $791,145 | 22.9% | - | Sep 3 | - | Toei Company |
| 5 | Ryoma! The Prince of Tennis | $2,398,192 | - | - | - | - | Sep 3 | - | Gaga |
| 6 | The first Gentleman | $2,079,276 | - | - | - | - | Sep 23 | - | Toei Company |
| 7 | Reminiscence | $1,671,252 | - | $574,466 | 34.4% | - | Sep 17 | - | Warner Bros. |
| 8 | The Courier | $896,941 | 108 | $248,084 | 27.7% | 108 | Sep 23 | - | Kino Films |
