Shizuka Nagare, universally known as "Iincho" (Chairman), holds the position of Class President in Okitsu High School's Class 2A. She pursued this role after her favorite pop star publicly praised class presidents, vowing lifelong dedication to the position—a commitment unwavering in her portrayal.

Highly intelligent and typically approachable toward peers and staff, Iincho reveals an intensely aggressive side when encountering perceived criticism or insults toward her idol, responding with disproportionate force. Her name, Shizuka, blends the characters for "quiet" with either "summer" or "fragrance," contrasting her occasionally volatile reactions.

Appearing as a teenage girl, she has dark brown hair styled in chest-length braids, green eyes, and wears glasses. She is consistently seen in her school uniform adorned with a bow. Classmate Gen "Old Man" Nakamura exhibits subtle hints of romantic interest toward her, though this remains undeveloped.

Iincho actively engages in class activities like cultural festivals and a Snow White play. During critical events—such as potential teacher Mika Suzuki's departure due to marriage—she shares distress with classmates, reflecting her investment in class stability. Her admiration for pop star Koro-chan surfaces in enthusiastic declarations, occasionally peppered with English phrases.