Ui Wakana holds the position of student council president at Seifu High School, elected following a campaign promoting love where she distributed condoms during her speech. Her capable public leadership sharply contrasts with her private life, where she lives with Hayato Izumi under an arranged marriage agreement between their families. At home, she exhibits dependency, frequently slacking off and relying on Hayato for household chores like cooking, despite her energetic and cheerful school persona.

A recurring visual element involves baby chicks appearing atop her head during states of depression, jealousy, or pensiveness, signaling her emotional state. Romantically inexperienced, she actively seeks to please Hayato through physical advances but often misjudges appropriate methods, highlighting her relationship naivety. Her childhood aspiration to marry Hayato later resurfaces, explaining her persistence in their dynamic.

Physically, Ui possesses brown hair, violet eyes, and a distinctive snaggletooth. Her character design frequently emphasizes her figure, particularly in domestic scenes involving states of undress. She develops an inferiority complex about her breast size compared to Rin Misumi, the disciplinary committee head, intensifying her jealousy and emotional vulnerability.

Her interactions with Rin extend beyond physical envy into ideological conflict: Ui's advocacy for liberalized romance clashes with Rin's strict enforcement of school morals. This rivalry deepens as both compete for Hayato's attention, though Ui remains openly affectionate despite her insecurities.

Her parents, Misato and Ryuji Wakana, appear occasionally; Misato's youthful appearance leads others to mistake her for Ui's sister. The family shares a trait where small animals manifest during pensive moments—chicks for Ui, rats for Ryuji.