The ninth night of New Japan Cup 2021 took place on March 15, 2021, at Korakuen Hall in Tokyo, Japan, and featured two second-round matches.
| Actor | Role |
|---|---|
 Hiroshi TanahashiHiroshi Tanahashi | Hiroshi Tanahashi |
 Jamie WhiteJay White | Jay White |
 Nobuo YoshihashiYOSHI-HASHI | YOSHI-HASHI |
 David Stephen Finlay IIIDavid Finlay | David Finlay |
 Hirooki GotoHirooki Goto | Hirooki Goto |
 Ryusuke TaguchiRyusuke Taguchi | Ryusuke Taguchi |
 Yuji NagataYuji Nagata | Yuji Nagata |
 Tetsuya ShimizuBUSHI | BUSHI |
 Seiya SanadaSANADA | SANADA |
 Shin TakagiShingo Takagi | Shingo Takagi |
 Taichiro MakiTaichi | Taichi |
 Yoshinobu KanemaruYoshinobu Kanemaru | Yoshinobu Kanemaru |
 Luke James Uggles EatwellZack Sabre Jr. | Zack Sabre Jr. |
 Tomoyuki OkaGreat-O-Khan | Great-O-Khan |
 Jeffrey CobbJeff Cobb | Jeff Cobb |
 William OspreayWill Ospreay | Will Ospreay |
 Tatsuya HayamaDOUKI | DOUKI |
 Kyosuke MikamiEl Desperado | El Desperado |
 Minoru SuzukiMinoru Suzuki | Minoru Suzuki |
 Shoji AkiyoshiJado | Jado |
 Kenta KobayashiKENTA | KENTA |
 Taiji IshimoriTaiji Ishimori | Taiji Ishimori |