Princess Peach Showtime!

One of Princess Peach's Toads receives a flyer advertising plays at the Sparkle Theater. Intrigued, Peach decides to attend the theater, accompanied by two of her Toads. As they arrive, a wicked sorceress named Grape and her minions, the Sour Bunch, invade and take over the theater, trapping many visitors inside the building, including Peach, who loses her crown during the commotion. Peach then meets Stella, the Sparkle Theater's guardian, and agrees to help her restore the theater. Making their way throughout all of the different plays, Peach and Stella work to rescue the Sparklas, who are the stars of all of the theater's plays.

After rescuing all of the Sparklas from the Sour Bunch, Peach assumes the form of Radiant Peach and confronts Grape at the theater's bottom floor, where the latter is eventually reduced to nothing more than her mask. However, Grape regains power and transforms into a giant version of herself, destroying the theater in the process. With support from the Theets, Peach and Stella resume battling Grape and eventually defeat her before restoring the theater to its original state. During the credits sequence, Peach performs with the Sparklas and reunites with the Toads, who give her crown back.