Nico Yazawa is a third-year student at Otonokizaka Academy and a member of the school idol group μ's, specifically the subunit BiBi, with pink as her image color. She projects an energetic idol persona defined by her signature "Nico Nico Nii!" catchphrase and pose, radiating exaggerated cuteness and confidence. This outward performance often contrasts with her naturally more abrasive, moody, and short-tempered personality, where she readily boasts about her own idol prowess while dismissing others. Her life involves significant family responsibility. She comes from a financially constrained single-parent household, with her mother frequently absent due to work. As the eldest sibling to sisters Cocoro and Cocoa and brother Cotaro, Nico shoulders the role of primary caretaker, managing household chores and cooking. She excels at domestic tasks, particularly making fried rice, though she initially denied cooking to uphold a privileged image. To maintain her siblings' admiration, she fabricates stories about her prominence in μ's, altering posters to show herself as the center and claiming other members are her backup dancers. This deception stems from a desire to inspire her siblings and shield them from her own past failures. Before μ's, Nico founded an idol group in her first year, but it dissolved when members quit under her unrealistically high standards, leading to isolation and resentment towards newer groups. She initially opposed μ's using her Idol Research Club room, doubting their dedication. Nico eventually joined after recognizing their determination and seeing an opportunity to guide them with her deep knowledge of idol culture, including stage personas, catchphrases, and performance techniques, which proved vital to μ's growth. Her commitment to idols as symbols of happiness, driven by a desire to make others smile, originates from using her father-taught "Nico Nico Nii!" to cheer her family during hardships. Her obsession with the spotlight and validation is partly fueled by a lack of parental attention. Despite her vanity, she exhibits genuine care for the group, notably mentoring Hanayo and later passing the Idol Research Club presidency to her. Nico frequently clashes with Maki Nishikino due to personality differences and harbors jealousy towards Eli Ayase's maturity and beauty, though these relationships evolve into mutual respect. Nico's development reveals emotional vulnerability. She reacts intensely to setbacks, like Honoka considering disbanding μ's, triggering fears of repeating past failure. Winning the Love Live competition brings profound relief and joy, culminating in intense tears as years of struggle resolve in achieving her dream. Post-graduation, she continues supporting μ's indirectly while focusing on family duties. Physically, Nico has long black hair typically in twin tails, crimson eyes, and a petite stature (154 cm). She often wears a pink sweater over her uniform, symbolizing her idol-focused femininity. Her role includes collaborating as a wardrobe supervisor with Kotori Minami on costume designs, and she possesses skill in hair arrangement. She dislikes spicy food, enjoys sweets, and often carries candies or lozenges. Personal writings like diary entries highlight her dedication to idol research, struggles with self-image, dieting attempts, and embarrassment about her physical development.