Not to be confused with another game of the same name

Mario and his friends must save the Multiverse from a team of Bowsers and meet alternate dimension versions of themselves along the way

Story

One day after Super Mario and The Anti-Dimension Bowser attempts to team up with other versions of himself from across the Multiverse when Mario, Luigi, Wario, Waluigi, Peach and Toad show up and try to stop him but as Mario and his friends fight Bowser and his minions in an attempt to stop them the machine Bowser is using explodes creating a dimensional portal similar that sucks things up in a very similar way to The Void, Mario wakes up in another Dimension and realizes his friends were separated from him and scattered across the multiverse, meanwhile Bowser wakes up in a mysterious castle that looks like a much more advanced version of his castle as then he sees a group of different versions of himself sitting on a series of villainous chairs, those different versions are Paper Bowser (From the Paper Mario games and Mario and Luigi Paper Jam), Baby Bowser (Although it's not the same version from past games), The Bowser from the 2023 movie, President Bowser Koopa (From The 1993 Mario Movie) and King Koopa (From The Super Show)