"Popin Q" is a fantasy anime film that intertwines elements of magical realism and coming-of-age themes. The narrative centers around five high school girls—Isami Tsuburai, Eriko Aizawa, Saki Nagareyama, Airi Mitsui, and Kotone Hitomi—each grappling with personal struggles and uncertainties about their futures. On the day of their graduation rehearsal, they are mysteriously transported to a parallel world called the "Time Axis," which is on the brink of collapse due to the imbalance caused by the "Time Stones." These stones, representing the flow of time, are essential for maintaining harmony in both their world and the Time Axis.

The girls encounter a young boy named Dippa, who explains that they have been chosen to save the Time Axis by mastering the art of dance. Through synchronized dancing, they can restore the Time Stones and prevent the impending destruction. As they train and perform together, the girls confront their individual fears, insecurities, and unresolved emotions. Isami struggles with self-doubt and the pressure to conform to societal expectations, while Eriko faces the challenge of reconciling her passion for dance with her academic responsibilities. Saki deals with feelings of isolation and the fear of being left behind, Airi grapples with her perfectionism and fear of failure, and Kotone confronts her reluctance to open up to others.

Their journey is marked by a series of trials that test their teamwork, resilience, and ability to trust one another. As they grow closer and learn to express themselves through dance, they gradually unlock the power needed to restore the Time Stones. The climax sees the girls performing a final, transformative dance that not only saves the Time Axis but also helps them gain clarity and confidence about their futures. The film concludes with the girls returning to their world, empowered by their experiences and ready to face their individual paths with renewed determination.