After the breakup of their previous band, guitarist Yuki and drummer Santa form a new group. They recruit bassist Towa, young guitarist Atsuro, and, after much persuasion, vocalist Sakuya. The quartet becomes Lucifer and faces the challenges of breaking into the music industry while maintaining unity. They also confront personal obstacles such as parental disapproval and the looming success of their former bands. Among them, Sakuya bears the most turmoil, struggling with a tragic past and his relationship with teenage lyricist Aine.