Konatsu Miyamoto, a high school student with light brown hair cascading past her shoulders and warm brown eyes, dons her crisp school uniform—a white blouse layered under a cream sweater vest, paired with a blue skirt, navy socks, and brown shoes. A red tie adds a pop of color, while green headphones crown her head during solitary singing sessions. Her vibrant personality blends relentless ambition, steadfast loyalty to friends, and a streak of stubbornness.

After stage fright shatters her confidence during a vocal music club performance, prompting the advisor to bar her from public singing, Konatsu refuses to surrender. She ingeniously merges the struggling choir with the badminton club, birthing the unconventional "Choir and Sometimes Badminton Club." Together, they compete in events like the Beach Singing Competition and debut original pieces such as "Shiokaze no Haamonii" (Harmony of Sea Breeze), showcasing her resourcefulness.

Driven by a musical passion inherited from her mother—a composer she deeply admires—Konatsu helps friend Wakana Sakai heal from grief by completing her late mother’s unfinished song. She champions music as a celebration of joy, defying institutional pressures to prioritize competition over creativity.

Years later, as a college student, she stays tethered to club life and high school friendships. A decade post-graduation, she reunites with old friends, now navigating adulthood’s complexities, including an unexpected pregnancy. Openly voicing her fears about motherhood and career balance, she leans on their support. Meanwhile, she mentors withdrawn student Yukine Kagamiya, drawing from her own past struggles to guide others.

Her younger brother, Makoto, occasionally aids her club endeavors, while her initially contentious rapport with music teacher Naoko Takakura matures into mutual respect, reflecting Konatsu’s unwavering dedication. Through triumphs and trials, her relationships thrive on reciprocity, resilience, and the quiet power of shared melodies.