Chika Nojima, also known by the designation of Rank A God Candidate, is a first-year high school student who attends the same school as the protagonist Goro. She is the sole member of the school's science research club, having effectively privatized the club room to convert it into a personal laboratory for her various projects. Her natural disposition is one of intense curiosity and spontaneity, which often leads her to take unpredictable actions that leave those around her, particularly Goro, feeling bewildered.

Behind this inquisitive exterior lies a more guarded and calculating individual. Chika is highly adept at concealing her true intentions, having learned to turn off her smartphone to hide her digital footprint and status as a God Candidate while she covertly gathers information on her competitors. Her motivations are deeply rooted in a troubled past. She harbored significant resentment toward her parents, who she felt would not allow her to live as she wished. This profound dissatisfaction drove her to attempt suicide, an act from which she was saved by another character named Ryo. This traumatic event forms the basis of her pre-existing and personal connection to both Ryo and Ryo's brother, Kyo.

In the narrative, Chika initially operates as an antagonist. She is revealed to be the individual behind a gas mask attack on Goro and his friends within the school's chemistry lab. Her role escalates during a confrontation on the hospital rooftop where Goro is recovering. She faces off against Honoka, initially holding the upper hand before being defeated when Honoka awakens to a more powerful form of her own ability. Following her defeat, rather than being eliminated, she is asked by Honoka to surrender and form an alliance, to which Chika agrees. This moment signals a shift in her role from a lone operative to a potential member of a larger faction. However, her newfound cooperation is immediately tested when she is critically wounded by an attack from Kyo's ability, only to be later saved and healed by Honoka.

Her key relationships are defined by these conflicts and connections. Her bond with Ryo is particularly significant, as Ryo is not only her savior but also a figure from her past who provides a sense of understanding and confidante. Her relationship with Kyo is more complex and dangerous, as he is both an acquaintance and a direct threat who ultimately attacks her. Her interactions with Goro and Honoka evolve from adversarial to cooperative, forming the core of her integration into the main group's struggle. Her development is marked by a trajectory from isolation and deep personal dissatisfaction to finding a place within a group, even if that path is fraught with violence and near-death experiences.

Chika possesses a notable ability known as Entropy Mask, which grants her control over fire. This power is not merely pyrokinesis but operates on a more fundamental level, allowing her to manipulate the chemical reactions of elements and flammable materials. She can trigger combustion through oxidation reactions, accelerate metal corrosion, and even cause detonations, giving her attacks an extremely high lethal potential. By controlling the heat generated from these reactions, she can launch devastating assaults against living targets. This scientific basis for her power reflects her background as a solitary researcher in the science club, blending her personality with her combat abilities.