Nobuko Ishihara is a supporting character in Lovely Complex. She is the best friend of Risa Koizumi and has been in a steady romantic relationship with Heikichi Nakao since their last year of junior high school. Nobuko, often called Nobu, is known for her affectionate and protective nature. She is deeply loyal to both Risa and Nakao and frequently looks out for their well-being, sometimes scolding Otani for being insensitive toward Risa or gently chiding Risa for allowing herself to be put in frustrating situations. She is generally wiser than her friends in matters of love and often offers advice, often orchestrating opportunities for Risa and Otani to spend time alone, though these plans do not always succeed.

Nobuko has a strong sense of personal style and chose her high school specifically because students could wear their own clothes instead of uniforms. She is fashion-forward and favors cute, flashy outfits, drawing inspiration from entertainer Masami Hisamoto. On her first day of school, her bold appearance even led Risa to mistake her for a foreigner. She has medium-length blonde, slightly wavy hair and pink eyes.

Her home life is shaped by her parents working, which led her to be raised by her grandmother, to whom she is very close. She is family-oriented and caring. In her own relationship, she is devoted to Nakao, calling him darling and dreaming of becoming his wife one day. The couple rarely argues and remains affectionate throughout the series.

Nobuko’s role is that of a supportive friend and a steady presence who helps guide the main romantic storyline through her matchmaking efforts and emotional support. Her primary motivation is the happiness of those she loves, and she consistently demonstrates loyalty, warmth, and a practical understanding of relationships. She does not undergo dramatic personal change but remains a reliable anchor for Risa and Nakao, offering comfort and counsel whenever needed.