As Raki is about to perform at Starlight Academy, her Aikatsu pass suddenly starts shining and she is pulled through another door. Raki arrives back in the Four Star Academy city and manages to interrupt a performance by the 25th generation S4, Hime Shiratori, Tsubasa Kisaragi, Yozora Kasumi, and Yuzu Nikaido. Luckily Yuzu manages to pass off the interruption as a prank on the other members and the concert continues. Afterward, Aine and Mio, who also managed to get pulled through the door, meet up with Yume Nijino and explain what happened to Hime and the others. Initially, Raki tries to pass it off as a lucky coincidence, but Tsubasa becomes angry with her at almost ruining their show. As punishment Raki becomes S4's assistant for the day and learns all about the hard work it takes for idols to shine.
らきが扉をくぐると――そこは、第２５代「Ｓ４」のステージのど真ん中だった！びっくりするらきだが、如月ツバサから厳しい一言を告げられ事の重大さを思い知らされる。反省したらきは、お詫びに「何でもする」と約束してしまい……？
