TRIGGER gathers at a bar on a chilly night to commemorate their second anniversary of working together as an idol group. Two years earlier, Ryuunosuke Tsunashi left his hometown in Okinawa and moved to Tokyo to pursue a career as an idol to repay his father’s debt. While waiting for his manager, he meets Gaku Yaotome, the son of Yaotome Productions' CEO, and the enigmatic Ten Kujou, the final member of the group. Gaku harbours doubts about Ten's position as the group's centre, and he wants to confront him. Fortunately, with the help of Ryuunosuke, the three of them quickly hit it off, and TRIGGER is birthed. However, they still have several obstacles to overcome before they achieve fame. In the meantime, their competitors, IDOLiSH7, must overcome their own series of problems. From scheduling leisure activities to resolving long-standing conflicts, they are ready to band together and confront their challenges head-on.