Chikage stands as the eldest among the twelve sisters, distinguished by her deep violet hair and matching lavender eyes, with a height of one hundred fifty-seven centimeters and a birthday on March sixth. Her outward appearance is marked by an air of profound mystery, often characterized by a reserved demeanor and minimal speech, which gives her the superficial traits of a stoic figure. However, beneath this placid exterior lies a notably passionate heart, and her quietness is better understood as introspection rather than a lack of emotion. She is deeply fascinated by the occult, the supernatural, and religious iconography, commonly associating herself with symbols such as the Christian cross and butterflies. Her private space reflects this interest; her room is habitually filled with burning candles, a large divination table, bottles containing various small creatures, and other arcane implements. She is a skilled practitioner of what could be termed dark or mystical arts, preferring to employ her magic through subtle means rather than overt displays of force.

Chikage's motivations are primarily driven by her intense and singular devotion to her brother, whom she addresses with the unique and slightly formal term anikun. She holds a fervent belief in a connection that transcends their current existence, claiming that she and her brother have been linked across multiple past lives, possibly as siblings or even as lovers. This conviction is symbolized by the cross she always wears, which she considers a vow of eternal union from a previous life. Her deepest desire is to live in a world apart with her brother, a solitary dream from which she wishes to exclude all others. Despite the intensity of this feeling, she is perceptive enough to recognize that her brother does not entirely share this wish, a realization she bears with a sensitive and quiet understanding. Among all the sisters, she is the only one who actively contemplates the possibility of taking her brother away from the others, and she has come close to executing such plans on several occasions.

In the narrative, Chikage serves as the resident occultist, frequently turning to her tarot cards, crystal ball, and other divination tools. Her unique abilities often position her as the one capable of addressing or explaining supernatural events that occur on the island, such as when her brother experienced a strange out-of-body episode. One of her most notable supernatural talents is the ability to summon and control a shadow entity known as Shadow Chikage. Although she prefers solitude and often keeps to herself, her role as the eldest sister does lead her to provide assistance when other sisters encounter difficulties, demonstrating a sense of responsibility that coexists with her reclusive nature. Her key relationships are largely defined by this dynamic; while she is generally distant from the other eleven sisters, she holds a possessive and deeply spiritual bond with her brother.

Over time, Chikage shows subtle hints of development. While her fundamental personality remains mysterious and her obsession with her brother persists, she gradually reveals a more vulnerable and longing side, moving away from being purely an enigmatic witch figure. Her primary arc involves reconciling her intense, otherworldly concept of love with the reality of her brother's feelings and his place in the wider family. Her journey is not one of becoming less mysterious, but rather of the person behind that mystery being seen, as she struggles to express an affection that is simultaneously possessive, sincere, and deeply rooted in a past only she remembers.