Lucky Sonoda may seem like an average middle schooler, but he is actually part of the Otogami septuplets, a family of musical prodigies. Unlike his six siblings, Lucky lacks their musical talent, causing tension with his accomplished pianist father. Following his parents' divorce, Lucky is ostracized from the family and lives with his harsh aunt. Despite his hardships, Lucky's love for the piano endures, especially when playing for his hospitalized mother. A turning point occurs when his mother wakes up and encourages Lucky to challenge his father's beliefs about talent. Motivated, Lucky auditions for Shibuya Music High School, where his distinctive style catches the eye of Hideo Dada, his father's former mentor. At the school, he receives mentorship from Dada and partners with Ako Furusu, who seeks retribution against Lucky's father for overshadowing her own mother in the music world.