Kasumi Toyama was enthralled by the stars as a young girl, so when she discovers a trail of star-shaped signs one day after transferring to a new school, she can't help but follow them. They lead her to a shop run by the grandmother of one of her new classmates, and Kasumi finds something that will change her life forever: a star-shaped guitar! And just like that, Kasumi knows that forming a band is her destiny. Of course, convincing Arisa and her grandmother to sell her the guitar won't be easy, and finding a group of other girls who want to become musicians will be even harder. But when a girl has stars in her eyes and a starbeat in her heart, there's nothing that will stop Kasumi from making her fantasies come true!

It's a new school year and Kasumi, Arisa, Saaya, Tae, and Rimi are thrilled to finally be second-year students. Even more exciting than becoming upperclassmen, however, is the fun they have while performing in their band Poppin' Party… until things get out of control when the girls publicly announce that they're going to do their own concert before they've really studied the issue. Suddenly they're committed to doing something that's a lot more difficult than it seemed, and the pressure is doubled since their musical rivals in Roselia, who've also announced a live concert, are way ahead of them in planning! But you can't stop the music, and with a little hard work and help from other groups and some talented newcomers, Poppin' Party fever will soon be popping up all over!

The girls of Poppin'Party have come a long way, but the competition coming up is the biggest yet - the BanG Dream! Girls Band challenge at the legendary Budokan! Slots to compete are limited and the usual competitors will be vying for the chance, but the band to beat is the new RAISE A SUILEN, whose founder, Chiyu, has sworn to destroy both Roselia and Poppin'Party! Indeed, Chiyu's main goal is to make Roselia's lead Yukina pay for denying Chiyu a spot as a producer, and the musical prodigy has the connections and resources to push the competition up to the next level! Can Poppin'Party keep up with the increased tempo and meet challenges like producing their own music video? They'll have to if they want to make it to the big show!