Cocoa Himezawa is a student in the same class as Kotaro Kawaii and appears as part of the main cast. She is easily recognized by the unique hair accessory she wears, which is shaped like small devil wings, contributing to her playful and mischievous look. Her overall style is distinctive and designed to stand out, which complements her strong desire to be noticed.

At her core, Cocoa is a direct, energetic, and attention-seeking individual who dreams of gaining widespread adoration as a social media star. She craves the spotlight and is constantly active online, posting a variety of videos in her pursuit of likes and followers. Her personality is bubbly and dramatic, and her enthusiasm often leads her to behave in eccentric and somewhat self-centered ways. Despite this confident exterior, she possesses a more sensitive side and demonstrates deep loyalty to those she considers close friends. Cocoa also has a very active and wild imagination, frequently fantasizing about being so popular that it becomes its own kind of problem.

Cocoa's primary motivation is to experience the thrill of online adoration. This desire drives her daily activities, which revolve around creating content, chasing trends, and managing her social media presence to captivate an audience. She is highly creative and uses her dramatic flair and social savvy to maintain an engaging persona. Her main skill lies in her ease with the tools and culture of social media, as she knows how to tailor her content to get reactions and keep her followers entertained.

Within the story, Cocoa's role is largely defined by her intense and often possessive relationship with her best friend, Hoshigari Chii. The two form an inseparable duo, and Cocoa is almost obsessively attached to Chii, frequently claiming that no one else could ever compare to her as a true friend. She is very supportive of Chii, demonstrated when she gives her handmade chocolate and a specific lip cream that Chii wanted for Valentine's Day. The depth of her attachment is further highlighted on Christmas, when she appears genuinely hurt upon learning that a cake Chii made was intended for her boyfriend. In contrast, a quiet moment on Christmas Eve, where the two share a meat bun on a convenience store bench, reinforces the warmth of their friendship.

While her friendship with Chii is the most significant, Cocoa also interacts with other characters. She was once caught by Gelee while performing a love spell, which led to an awkward moment where she had to plead for secrecy. Furthermore, she harbors a crush on a person whose initials are C.H., but she knows this person already has a partner and only sees her as a friend. She accepts this situation with a mix of self-deprecation and humor. There is a playful tension in her dynamic with Chii, and moments of jealousy or disappointment arise when Chii's attention turns to others.

Over the course of events, Cocoa shows a degree of development in her personal attachments. While she craves social media fame, her experiences often reaffirm that her most genuine and precious moments are the ones she shares with Chii. She demonstrates a capacity for self-reflection, as seen in her resigned but humorous acceptance of her unrequited feelings. She has also had moments of vulnerability, such as being flustered when her secret actions are discovered, which adds layers to her confident public persona.