A new school year has begun at Ayanagi Academy for Yuuta Hoshitani and the members of Team Ootori. As the school's annual graduation performance titled Shadow and Lights quickly approaches, the second-years in the Musical Department must participate in the production as part of their curriculum. Out of the 25 students in the division, five of them will receive a training role and actively participate as actors in the program alongside the graduating class. Attaining one of these coveted spots will not only increase a student's academic standing within the department, but it will also put them in the running for a position on the elite Kao Council. While every student in the department strives to obtain one of the five training roles, Team Yuzuriha's Riku Ageha is practically a front-runner for the role of Alexis' Shadow. Having idolized an Ayanagi alumnus' performance of Alexis, Ageha has spent a majority of his life perfecting the portrayal in hopes of being selected for the show. In contrast, Hoshitani's lack of experience in show business puts him at a great disadvantage for any of the roles in the production. With specialized training from the Ancients—former Kao Council members and Ayanagi alumni—the second-years give it their all as they aim for the stars and beyond.

Deep beneath the surface of Southern Cross Isle, a mysterious organization known as the Glittering Crux Brigade frequently gathers in their underground fortress. The group is particularly interested in Cybodies, stone giants which can transform into massive fighting humanoids but only in a realm known as Zero Time. By finding and shattering the seals of the island's four seal maidens, Glittering Crux hopes to break free of Zero Time and use the Cybodies anywhere they please. One night, a young man named Takuto Tsunashi washes up on the island's shore and is rescued by Sugata Shindou and his fiancée Wako Agemaki, one of the island's seal maidens. After he awakens, Takuto quickly befriends the two and proceeds to enroll at the local academy, where many of his fellow students are secretly members of Glittering Crux. However, Takuto holds a secret: when in Zero Time, he can utilize a Cybody of his own—the Tauburn. In the forthcoming battle, Takuto and the Tauburn will be the key to preventing Glittering Crux from shattering Wako's seal and realizing its nefarious ambitions.

When a meteor shower causes a mysterious star-shaped alien to land in Lala Hagoromo and Hikaru Hoshina's home, the girls find themselves having to take care of the mischievous creature whom they name Yuma. Although their relationship gets off to a rocky start, Lala and Yuma eventually connect through their similar passions for music and exploration. However, when strange alien hunters targeting Yuma arrive on Earth, the girls learn that there is more to Yuma than what meets the eye. In protecting Yuma, the Star☆Twinkle Precure find themselves entangled in an astronomical battle where the fate of the galaxy is at stake! Will Yuma feel the Precure's emotions through their melody, and can they make the necessary sacrifices to defend everything they love?

Yuuta Hibiki wakes up in the room of Rikka Takarada and notices two things: he has no memories, and he can hear a mysterious voice calling his name from a nearby room. On further inspection, he finds a robot—which introduces itself as Hyper Agent Gridman—behind the screen of an old computer. Much to Yuuta's surprise, Rikka cannot hear Gridman, nor can she see the ominous monsters looming over a thick fog as it envelopes the town outside. Another giant monster materializes in the city and proceeds to wreak havoc. Amidst the confusion, Yuuta is once again drawn to the old computer and merges with Gridman. Suddenly, he appears in the middle of the battle and is forced to fight the monster. Together with Rikka and fellow classmate Shou Utsumi, Yuuta forms the Gridman Alliance to defeat the monsters plaguing the city and find whoever is responsible for their emergence.