Amane Aika was told early on to become the best idol there ever was by her parents. Aika was too shy though so her oniichan Manaka said he’ll be an idol for her sake. Fast forward some years later, both of her parents now deceased, it’s the day of Manaka’s idol debut with the idol group Re;Rise. Aika is getting ready to go see her brother’s performance until she suddenly gets a mystery package from him. Inside she finds his clothes and a wig that looks like his hair with a message that says “don’t ask questions, just go impersonate me” Aika is shocked and decides to go to his band dorm house to check on his whereabouts. When she gets there, she runs into one of the members, Itsuki and he says that if she doesn’t do as her brother says, she’ll ruin his idol career. She decides to put on the disguise and act natural around the other members. Unfortunately for her, her brother Manaka was the only sane one in the whole group. The rest of the group members are a bunch of weirdos and it was their leader Manaka (who they call Aika-kun because that was his stage name) who kept them all together. The manager Yonezawa finds out the truth from Aika and he begs her to take her brother’s place for a bit until he returns…or else his intestines will explode from the stress. Aika is shy and worried about interacting with her absurd new group but decides she’ll try her best until her brother returns.