"IDOLiSH7 Second Beat!" continues the journey of the idol group IDOLiSH7 as they navigate the competitive and often challenging world of the entertainment industry. The series delves deeper into the personal and professional lives of the seven members—Riku Nanase, Tenn Kujo, Yamato Nikaido, Mitsuki Izumi, Tamaki Yotsuba, Sogo Osaka, and Nagi Rokuya—as they strive to achieve their dreams while facing new obstacles.

The narrative explores the complexities of fame, friendship, and self-discovery. IDOLiSH7 faces intense competition from rival groups such as TRIGGER and Re:vale, both of which have their own struggles and ambitions. The series highlights the pressures of maintaining public image, the demands of rigorous schedules, and the emotional toll of balancing personal aspirations with group dynamics.

Key plot points include IDOLiSH7's preparation for major performances and events, which test their unity and resolve. The group must confront internal conflicts, such as differing opinions on their artistic direction and the challenges of individual growth within a collective identity. External challenges also arise, including media scrutiny, rivalries, and the ever-present threat of being overshadowed by more established groups.

Character development is a central focus, with each member of IDOLiSH7 grappling with their own insecurities and aspirations. Riku's health issues and his determination to overcome them, Tenn's complex relationship with his brother and his own identity, Yamato's leadership struggles, Mitsuki's desire to prove himself, Tamaki's search for belonging, Sogo's hidden burdens, and Nagi's cultural adjustments all contribute to the rich, interwoven narrative.

The series also sheds light on the backstories of rival groups, providing a more nuanced understanding of their motivations and challenges. TRIGGER's members—Gaku Yaotome, Ryunosuke Tsunashi, and Tenn Kujo—face their own trials, including the pressures of maintaining their status and the personal sacrifices required for success. Re:vale, consisting of Momo and Yuki, deals with their own history and the evolving nature of their partnership.

"IDOLiSH7 Second Beat!" balances moments of intense drama with lighter, comedic elements, creating a dynamic and engaging storyline. The series emphasizes themes of perseverance, camaraderie, and the pursuit of dreams, making it a compelling continuation of the IDOLiSH7 saga.