Mirai Momoyama, Emo Moegi, and Rinka Aoba are 2nd year students at Kirarigaoka Middle School in Kirajuku, and together they form an idol group called "Miracle☆Kiratts"! The popularity of their streaming programs has skyrocketed! One day, a mysterious Pri☆Chan idol named "Dia" appears, and everyone is given a Jewel Pact. Along with that, she announces the opening of the "Jewel Auditions", an event where idols with a jewel-like shine are chosen to become "Jewel Idols". Only those who can pass the audition with a sparkling heart can make their "Kiratto Jewel" shine, allowing them to receive their "Jewel Coord". And out of all of them, only the best "Jewel Idol" can wear the long-admired "Diamond Coord". Who's going to be?!

(Source: PriChan Wiki, edited)