Daru Dayu, a wandering drummer shrouded in mystery, traverses the world cloaked within a daruma mascot—a temporary vessel veiling her true form. Her path crossed with musicians A and Un after witnessing their raw talent, leading her to mentor the duo and co-found the band Tsurezure Naru Ayatsuri Mugenan. Though her origins remain obscured, fragments of her past reveal stints as an inn worker. Driven by a zeal for exploration and pedagogy, she immerses herself in guiding protégés through events such as "The Dawn of Rhythm Game Culture" and "For the Future of My Students, I Will Dance!," while tackling challenges ranging from collaborative musical endeavors to pragmatic puzzles like "This Evening’s Dinner Is Exceptional" and "Well, Well... This Is Quite the Difficult Case, Isn’t It?"

Initially aloof, her interactions gradually soften during festivals and training camps, reflecting a nuanced evolution from enigma to approachable mentor. Adorned with purple hair, piercing yellow eyes, and subtle animalistic features, her concealed visage fuels curiosity. Ever watchful, she dispenses cryptic wisdom with measured calm, her motives and history lingering just beyond reach, as elusive as the figure hidden within the daruma’s hollow shell.