Mishima Dojo is a downloadable stage in Super Smash Bros. Ultimate based on the stage of the same name from Tekken 7. It released alongside Kazuya on June 29, 2021.
The stage is similar to King of Fighters Stadium in that the sides are walled off, though if fighters are launched hard enough into the walls and ceiling, they break off and reveal the outside of the dojo. The walls and ceiling repair themselves after a while. Heihachi Mishima also makes an appearance as a background character.