After Dai Star stage performers exploded in worldwide popularity in the 20th century, 16-year-old Kokona Ootori follows her dream of becoming a World Dai Star by auditioning for the Sirius theatrical troupe.

Ritsuka Uenoyama meets Mafuyu Sato one day in his normal napping spot. Ritsuka ends up fixing Mafuyu's guitar, which leads to Mafuyu pestering Ritsuka to teach him guitar over and over. Ritsuka declines over and over but somehow, after seeing how passionate Mafuyu is about learning guitar, Ritsuka starts to remember how he felt when he first started playing music.