Queen Koopa

-Princess Peach and Mario are finally going to get married, but

-Bowser interferes and kidnaps the Princess, so

-Mario goes to rescue the Princess, when

-Wendy O'Koopa, one of the mini-bosses, captures Mario in a cage, so

-Mario questions Wendy's motives for wanting to aid Bowser in taking over the Mushroom Kingdom, when

-Bowser and Wendy have some negative interactions, so

-Wendy lets Mario go to complete the mission, but

-Wendy comes in during the Bowser fight and kicks his ass herself, so

-Mario gives her a thumbs up or something affirmative like that, and

-Mario and Peach return to the Mushroom Kingdom to get married, but

-Wendy shows up at the wedding in the clown flying thing and fires a bullet bill at the princess, presumably killing her, so

-Some Toad guards back her up against a wall, but

-She has an interaction with Mario from across the ballroom, while he's huddled over the Princess's body, explaining that she assumed Mario wanted to marry the Princess for the same reason Bowser did: to take over the Mushroom Kingdom; and now that the Princess and Mario are married, and she's out of the way, Mario is the rightful king, and for his wedding present: Mario and Wendy can live happily ever after! But

-Mario is visibly unhappy about this, so

-She beats off the Toads and uses her wand to freeze the Princess's body in an item box, and takes it away out the window, so

-Mario pursues her

-Wendy goes to Kamek, and knocks him out and ties him up.

-When he awakens, Wendy demands he tell him how to bring the Princess back to life, so

-He reluctantly tells her that King Wart has something, like a one-up or a powerstar or something like that he's been using to oppress the people of SubCon as and immortal for a century or so, so

-After getting Kamek to spill directions, Wendy continues her journey to SubCon, when

-Mario shows up shortly after to find Kamek tied up, who tells him where Wendy went, so

-Mario hijacks a Lakitu cloud and forces Kamek to guide him to SubCon.
-Wendy gets to the outskirts of SubCon and finds Waluigi living in a shack, who guides her through a shyguy city, which is visibly poor and oppressed by a sort of police state, so

-Wendy rescues Birdo, who she rides the rest of the way to Wart's castle to do battle, so
-They fight, and she cuts his head off and throws it out the window, because it totally doesn't kill him,

-She gets the item, and gives it to the Princess, when

-Mario shows up, and sees the Princess revives,

-Having undone the murder, Mario and the Princess no longer see her as an enemy, but 

-They all agree she probably doesn't have good enough PR to return to the Mushroom Kingdom, or to her home wherever Bowser comes from, when

-Out the window, the citizens of the shyguy city, who saw the head of Wart descend from the window are hailing her as a hero, and the new Queen of SubCon, so

-She decides to stay behind, however

-Some Wart loyalists return his head to his body, so

-Wendy stays with Waluigi on the outskirts for awhile, but

-Finds she can't stay out of things for long, as 

-A resistance has begun in SubCon, and rebels are spraypainting "long live Queen Koopa" on the walls and stuff

-Story ends with Wendy, Birdo, and Waluigi setting out to save the day again.