Chika Minazuki is the younger cousin of Taeko Minazuki and a student in her first year of high school. She initially lives in a seaside town, where she spends most of her summer vacations working at her grandmother's beachside cafe. This job results in her having a very tanned complexion, complete with tan lines from wearing a swimsuit.

Chika is known for her energetic and cheerful personality, which brings a lively presence to the household. She moves into the Sakuraba house, initially to complete her homework before the new school year begins, and later transfers to a local school. Her role in the story is largely that of a catalyst, as she is not afraid to ask the other characters direct and awkward questions about their feelings, serving as a perspective that stirs up the group's hidden emotions. She notices her cousin Taeko's crush on Kaoru Hanabishi and spends time trying to arrange situations to bring the two of them together.

Over the course of the series, Chika develops her own mild romantic feelings for Kaoru, but for the most part, she looks up to him as an older brother figure and even addresses him with a term meaning "big brother". Her other key relationships are with the girls of the Sakuraba house, including Aoi Sakuraba, Tina Foster, and Mayu Miyuki, as she integrates into their group dynamic. She is also a member of her school's swimming club.

Chika is a first-year high school student with dark brown hair and green eyes. Unlike many of the other characters who have lived in the house for years, she arrives as a new resident in the second season, Ai Yori Aoshi ~Enishi~, and her presence immediately causes changes and challenges for the established residents. She is frequently seen carrying a small doll made in Kaoru's likeness.