On a chilly night, the idol group TRIGGER gathers at a bar to mark the anniversary of when they began working together. Two years earlier, Ryuunosuke Tsunashi departs from his home in Okinawa for Tokyo, aiming to become an idol and settle his father's debt. While waiting for his manager, he is picked up by Gaku Yaotome—the son of the CEO of Yaotome Productions and Ryuunosuke's future colleague—and they proceed to meet the enigmatic Ten Kujou, the final member of the group. Gaku intends to confront Ten, as he is skeptical about Ten's role as the group's center. Fortunately, with Ryuunosuke's assistance, the three manage to get along, and TRIGGER is formed. However, obstacles still remain that they must overcome before achieving fame. In the present day, their rivals, IDOLiSH7, face their own set of issues. From deciding how to spend their free days to resolving a long-standing dispute, they are prepared to work together and tackle these problems directly.