Alba, originally named Yoko Tanaka, is a 14-year-old aspiring singer who travels to Tokyo to chase her dreams in the entertainment industry. Her journey begins on a bullet train where she meets her future best friend, Saki Yamamori. Both girls are soon scouted in Shibuya by talent manager Toshio Harada. Visually distinctive with pink hair, Alba often styles it in girlish pigtails that sometimes form heart shapes during performances, reflecting her strong association with the color pink.

Despite lacking formal training, Alba displays remarkable versatility, excelling academically, athletically, and musically. Her compelling natural singing voice fuels her rapid ascent in the idol world under the stage name "Yokkyun." A constant companion is her flying squirrel, frequently seen perched on her head or shoulders during daily life and adventures.

Alba embodies the genki girl archetype, defined by unwavering optimism and a perpetually cheerful disposition. She constantly smiles and finds positivity even in difficult situations, often countering Saki's pessimistic outlook with her own idealism, cementing their dynamic as foils. This persistent encouragement extends to others, including her employer Hideki Yamashita, whom she helps overcome his defeatist attitude. Her idealism fosters a strong sense of personal honor and trust, sometimes leading to naiveté. She also expresses a fascination with Indian culture, wearing traditional clothing and voicing fondness for Indian cuisine.

Her core development focuses on the impact of her positivity, gradually inspiring Saki, Hideki, and others to embrace more hopeful perspectives. Within the series, she grows from a countryside newcomer into an influential figure navigating the Tokyo entertainment scene, leveraging both her diverse talents and vibrant personality.