Chitose Kaginoji is a supporting character in this romantic comedy series. She is a fourteen-year-old girl with a youthful appearance, characterized by her long, wavy blonde hair and orange eyes, and often wears a hair bow. Chitose comes from a wealthy and privileged family, having access to considerable resources, including personal maids and private transportation. Her connection to the main female lead, Tsukasa, predates the main story, as Tsukasa lived with Chitose prior to her marriage. This arrangement stemmed from an incident in their past when Tsukasa saved a young Chitose from falling off a cliff.

Chitose harbors an intense and possessive adoration for Tsukasa, whom she calls sister, though they are not blood-related. Her central motivation is her deep-seated belief that she owes her life to Tsukasa and that Nasa Yuzaki, Tsukasa’s new husband, is unworthy of her. As such, her primary role in the story is that of a comedic antagonist who constantly schemes to sabotage Nasa and Tsukasa's marriage in the hope of winning Tsukasa back for herself. Her schemes are often elaborate, fueled by her explosive and dramatic personality, and can involve her maids in actions like kidnapping, blackmail, or the publication of fake photographs to ruin Nasa's image. Despite her high energy and tendency to scheme, Chitose also displays a more vulnerable and whining side, especially when her plans fail or she feels ignored by Tsukasa. Her personality is described as naturally tsundere, and she is known for being straightforward, often taking Tsukasa’s jokes seriously.

Key to her role are her relationships with other characters. Her two maids, Charlotte and Aurora, are often seen assisting her with her various plots, with Charlotte being notably bold while Aurora is more reserved. Her relationship with Nasa is openly antagonistic, as she constantly tests him and attempts to prove he is not good enough for Tsukasa. While she begins as a forceful opponent to the marriage, her stance shows hints of development. After Nasa asserted that they married to prove their love, she appeared momentarily convinced, though she continues to make regular appearances to check on the couple, indicating a slow, reluctant acceptance of their relationship. Beyond her scheming, Chitose possesses some notable abilities. She is portrayed as a skilled video game player, having honed her abilities in an effort to keep Tsukasa's attention and be a worthy sparring partner for her.