Kizuna Hyūga is a second-year student at St. Lulim Girls' School, recognizable by her light brown hair styled in two high pigtails, brown eyes, and pink school uniform.

She bursts with energy, displaying an outgoing, hyperactive, and openly enthusiastic personality. Kizuna introduces herself to new people without hesitation. While determined and dedicated to her club activities, she can also be immature and klutzy compared to peers. Her closest bond is with her best friend, Remon Natsume. The two are constantly together, often holding hands, touching, and occasionally sharing a bed. Their relationship includes moments like Kizuna kissing Remon as a distraction during a thumb-wrestling match and participating in cosplay events, with Kizuna as a princess alongside Remon dressed as a prince; the exact nature of their connection remains ambiguous.

Kizuna deeply admires Chikaru Minamoto, her senpai and the student council president. She enthusiastically supports Chikaru's decisions and follows her club involvement, even proposing Chikaru pair with Amane Ohtori for the Etoile selection.

An active member of both the Transformation Club and Secret Club, Kizuna collaborates with Remon, Tsubomi, Kagome, and Chiyo on club projects and events. During a cultural festival, she expressed a desire to play Romeo. Her high energy levels and constant activity sometimes annoy Remon. Her surname "Hyūga" (日向) means "sunny place" and is shared with Hinata Hyūga from the *Naruto* series, though no further connection is established.