"The School Festival and the Secret Promise" is the ninth episode of Pretty Rhythm Aurora Dream and the ninth episode of the entire Pretty Rhythm series.
After Rizumu discovers that the previous winner of the Tiara Cup was Sonata Kanzaki, she works relentlessly to see to it that she wins. But in her attempts to improve her relationship with others starts to suffer.
One late evening, Rizumu is watching a performance of a figure that resembles her. She skates along the ice before jumping up into the air to perform Aurora Rising. She wonders if she too can do it and continues to watch.
The following day, Kyoko informs Aira and Rizumu that in June the two of them will be taking part in a tournament. Jun brings up the wonderful stone the winner will be receiving from it and goes on to describe the legendary Prism Queen, Sonata Kanzaki, who won it, which led to her gaining a lot of attention and later granted her the ability to perform Aurora Rising. While Aira gushes over the tiara, Rizumu is distracted and soon takes off for home. Jun continues on to describe how one needs the Pure Crystal Tiara, Crystal High Heels, and the Pure White Wedding in order to perform the Aurora Rising. He also tells her that to perform it, the user must love Prism Shows and symbolically wed yourself to the rink. Which causes Aira to think about how serious Rizumu is in regards to performing this, although she seemed sad.
At school, Aira spots the sign for the upcoming school festival. She spots the sign with an image of a secret guest star appearance, and she wonders if the guest may be Callings, although she sorta doubts it. She excitedly starts to tell Rizumu about it, only to be cut off when Rizumu claims she cannot go. Before Aira can ask, they are approached by a few girls who ask them to perform at the festival as special guests, because they were unable to get the Callings. They explain how they called Kyoko, but she was sure if Callings appeared it would ruin the event, so she suggested Aira and Rizumu instead. While Aira would not mind helping out, Rizumu insists that if they have the time to help the festival then she would rather use this time to practice for the Tiara Cup. She then runs off, so with no choice, Aira accepts to help them out.
Aira and Rabi-chi sit down to discuss the problem with Rizumu. Aira was so sure that she would be excited about the festival, while Rabi-chi reminds her that even if she is busy preparing for the contest she can't just shirk her other work. Aira agrees so they determine that she must be in a slump.
Meanwhile, Rizumu is training at Pretty Top. She gets angry when she realizes she almost fell over and messed up, and Bea-Chi insists that she stops to rest for a moment. Rizumu refuses, however, and to her surprise, Hibiki shows up. He teases her before suggesting that she loosen up a little, and then he leaves again. Even more frustrated, Rizumu claims that she does not have the time for anything else right now.
The next day at school, Rizumu overlooks the festival sign again. Aira approaches her and reveals her plan to take part in the Prism Show during the Festival. She also plans to train and do her best for the Tiara Cup too, so she is hoping that Rizumu will perform with her. Rizumu is surprised by this but tells her that if she was to go after both things, she will just fail both of them, so she refuses. She also insists that Aira reconsiders, before telling her not to care about making others happy, since she has better things to worry about. Aira tells her that she wants everyone to have fun, including Rizumu, pointing out that she hasn't been having fun lately, which causes Rizumu to think back to what Hibiki told her. Aira continues on by saying that Rizumu was the one who showed her how fun the Prism Shows were, to begin with, so she tells Rizumu that she will do her best and she will wait for her before running off.
Later on in the day, Rizumu is out for a run when she happens to spot someone dancing nearby. She is very surprised when she realizes it is Hibiki, and she stops to chat with him. He offers her a drink and explains how he always comes to this secret location to train. She believes she could never dance as well as him, and she admits that she thought he never practiced. Hibiki explains the importance of practicing, because not only does one get to show how much fun they have, but it makes the audience members enjoy themselves, which is the most important thing. He teases Rizumu a little again before promising that she can come back to tell him things whenever she feels troubled.
During the Festival, Rizumu walks around when she spots the brand new poster that was put up. Aira insists that Rizumu will be showing up when the two girls come to find that she still is not there yet. She is sure she will come when suddenly the Callings arrive. They explain how they couldn't just leave girls in trouble, so they showed up to perform, as requested.
As this is going on, Rizumu hears the music begin to play and she goes into the nearby room, where they are performing. She watches them before going to meet with Aira, who she quickly apologizes to upon reaching the room. Aira insists that it is okay though since she knows how much she wants to win this Tournament. So after she changes they run to the sidelines and wait for their turn, then after speaking to Callings they get on stage. Rizumu performs Colorful Choco Parade and realizes afterward that bringing People happiness really is a nice thing. She wants to see more people smile and thinks about how she has never felt this before. As Aira goes on to perform Heartful Splash, Rizumu realizes she has enough energy and jumps up to perform another Prism Jump, this time Happy Macaron Spin.
With their show over, the girls head backstage to relax. Callings come by again to tell the girls that they will be heading out now, but Rizumu stops them to speak to Hibiki. At first, she is flustered, but she finds herself charged and angry when he starts to tease her again. As the boys walk off, the other two wonder what Hibiki happened to say, but Aira is just happy that Rizumu is back to normal.
Their happiness is short lived though when Jun shows up to tell them that there is a single Tiara. While the girls may compete together, only one of them will be able to bask in the spotlight of glory, which causes the girls to stare with disbelief.