"Love Live! Superstar!!" is set in Yuigaoka Girls' High School, a newly established institution in the Odaiba area of Tokyo. The series centers on a group of students who form a school idol group to save their school from potential closure due to low enrollment. The protagonist, Kanon Shibuya, is a first-year student with a passion for singing but struggles with stage fright. Her life changes when she meets Tang Keke, a transfer student from Shanghai, who encourages her to pursue her dreams. Together, they decide to form a school idol group, inspired by the success of other idol groups in the "Love Live!" universe.

As the story progresses, more members join the group, each bringing their unique personalities and talents. Chisato Arashi, a childhood friend of Kanon, initially opposes the idea of becoming an idol due to her focus on academics but eventually joins after realizing the importance of following her passions. Sumire Heanna, a wealthy and confident student, joins to prove her capabilities beyond her family's expectations. Ren Hazuki, a shy and reserved girl with a love for music, also becomes a member, contributing her skills as a songwriter. The group names themselves "Liella!" and begins their journey to compete in the Love Live! competition, a prestigious event for school idols.

The narrative explores the challenges of balancing school life, personal struggles, and the demands of being an idol. The members of Liella! face obstacles such as self-doubt, rivalry with other idol groups, and the pressure to succeed. Through teamwork and perseverance, they grow individually and as a group, learning to overcome their fears and insecurities. The series emphasizes themes of friendship, determination, and the pursuit of dreams, staying true to the core values of the "Love Live!" franchise.

As Liella! gains popularity, they attract the attention of other schools and idol groups, leading to both friendly and competitive interactions. The story culminates in their participation in the Love Live! competition, where they aim to prove their worth and bring recognition to Yuigaoka Girls' High School. The series balances lighthearted moments with emotional depth, showcasing the characters' growth and the bonds they form along the way.