Alessandra Susu, a 14-year-old member of the idol group 777☆SISTERS and its subunits NI+CORA and SU♡SUTA, carries herself with a maturity beyond her years, adopting a poised, model-like demeanor. She seamlessly weaves English phrases into her fluent Japanese, a habit accentuated by her tanned complexion and striking features, often leading others to assume she is a foreign celebrity. Discovered at an airport during her arrival for a school exchange program, she was scouted by a manager and Coney Rokusaki, who spotted her innate potential. Though outwardly confident, she privately battles homesickness, her nights occasionally marked by tears of loneliness. Her background hints at foreign heritage, though her exact nationality remains undefined.

The Italian-derived name "Alessandra," meaning "defender of men," serves as her first name, while "Susu" is her middle name, as revealed in NI+CORA’s inaugural storyline. She shares an October 17 birthday with fellow idol Rinko Shirokane. A playful affection defines her interactions, most notably her habit of addressing the manager as "Darling," blending charm with lighthearted teasing.