RIZIN 12 live from the Aichi Prefectural Gymnasium in Nagoya, Japan, for the first time. The main event of the evening features the consensus No. 1 lightweight in RIZIN, Yusuke Yachi, taking on late-replacement opponent Luiz Gustavo. Yachi rides a six-fight winning streak into the ring following wins against UFC veterans Diego Nunes, Takanori Gomi and Daron Cruickshank. Gustavo comes in with a lengthy winning streak of his own into his promotional debut. Gustavo has stoppages in all eight of his professional wins.
| Actor | Role |
|---|---|
| YYusuke YachiNot listed | Not listed |
| LLuiz GustavoNot listed | Not listed |
| YYuki MotoyaNot listed | Not listed |
| KKazuma SoneNot listed | Not listed |
 Kiichi KunimotoNot listed | Not listed |
| RRyuichiro SumimuraNot listed | Not listed |
 Kaitlin YoungNot listed | Not listed |
| RReina MiuraNot listed | Not listed |
| TTaiki NaitoNot listed | Not listed |
| HHannya HashimotoNot listed | Not listed |
 Mikuru AsakuraNot listed | Not listed |
 Hatsu HiokiNot listed | Not listed |
| RRoque MartinezNot listed | Not listed |
| KKiyoshi KuwabaraNot listed | Not listed |
 Kaito OnoNot listed | Not listed |
| SSho OgawaNot listed | Not listed |
 Kanako MurataNot listed | Not listed |
 Angela MagañaNot listed | Not listed |
| RRyuki KanedaNot listed | Not listed |
| SShintaro MatsukuraNot listed | Not listed |
| TTakahiro OkuyamaNot listed | Not listed |
| SShota TakiyaNot listed | Not listed |
| SShuto SatoNot listed | Not listed |
| NNaoyaNot listed | Not listed |