Saki Uno is a typical 15-year-old girl with a side gig as a member of the infamously hated idol duet Magical Twins. Despite this, she enjoys spending time with her closest friend Sakuyo Mikage while she works to grow closer to her childhood obsession, Sakuyo's brother Mohiro. Her tranquil existence is shattered when she discovers a yakuza-looking man attempting to enter her home. Forced to let him in, Saki discovers that her mother was once a demon-fighting Magical Girl, and that her obnoxious visitor is actually a mascot named Kokoro-chan seeking for a replacement. Saki is perplexed and suspicious of the request until Kokoro-chan tells that Mohiro is a target of some charming, squirrel-tailed demons.