"LIP×LIP FILM×LIVE: Kono Sekai no Tanoshimikata" centers on the lives of two high school boys, Yūjirō Someya and Aizō Shibasaki, who form the idol unit LIP×LIP. The series explores their journey as they navigate the challenges of balancing their personal lives, school responsibilities, and burgeoning careers as idols. Yūjirō, a charismatic and confident individual, contrasts with Aizō, who is more reserved and introspective. Their dynamic personalities create both synergy and tension, which becomes a driving force in their relationship and performances.

The narrative delves into the pressures of fame, as the duo faces the expectations of their fans, the demands of their agency, and the scrutiny of the public eye. Their interactions with classmates, family, and industry professionals reveal the complexities of their lives beyond the stage. The story also highlights their growth as individuals and as a team, showcasing their struggles with self-doubt, rivalry, and the pursuit of their dreams.

Key supporting characters include their manager, who provides guidance and support, and their classmates, who offer glimpses into the normalcy they often miss. The series balances moments of lighthearted humor with deeper emotional arcs, particularly as Yūjirō and Aizō confront their insecurities and the sacrifices required to succeed in the competitive world of entertainment.

The plot intertwines their professional endeavors with personal challenges, such as maintaining friendships, dealing with jealousy, and finding their authentic selves amidst the performative nature of their careers. Through concerts, rehearsals, and everyday interactions, the series paints a multifaceted portrait of the idol industry and the individuals who strive to thrive within it. The narrative emphasizes themes of perseverance, identity, and the importance of human connection, offering a grounded yet aspirational look at the lives of its protagonists.