Spoiler Alert! This article or section contains details not covered in the anime. Do not proceed unless you wish to be spoiled.
Family[]
Daichi Fujiwara[]
Daichi Fujiwara is Chika's father, who is overly protective. Since he doesn't want her to end up like her older sister, he is also strict with her, as seen when he doesn't allow her to wear her shirt tied above her stomach.
Maho Fujiwara[]
Maho Fujiwara is Chika's mother.
Moeha Fujiwara[]
Moeha Fujiwara is Chika's little sister.
Toyomi Fujiwara[]
Toyomi Fujiwara is Chika's elder sister.
Pes[]
Pes is Chika's pet dog. She is very fond of him.
Philly[]
Philly is Chika's pet fish.
Student Council[]
Kaguya Shinomiya[]
Kaguya Shinomiya has been close friends with Chika since middle school. She also confessed to liking Kaguya so much that if they were stuck, holding a rope to prevent falling from a cliff and her weight is causing the rope to start to rip, she will let go of the rope to let Kaguya escape instead.
Miyuki Shirogane[]
She has engaged Miyuki Shirogane in harsh tutoring sessions in volleyball, singing and dancing. She faces him with cruel comments on his skills but also works with him to improve it. She considers Miyuki as akin to a son as shown by her crying with the quote "I raised that boy myself", "They grow up so fast!" at times when Miyuki has achieved something he was never able to do before she taught him.
Repeated exposure to his lack of skill has caused her to develop PTSD-like symptoms, and it ends up being triggered whenever the subject of helping him (or discussing any of the topics that she already taught him) is brought up. Despite this, Chika is uncomfortable with the idea of someone else teaching Miyuki a new feat and has shown to be somewhat possessive of her position as his teacher.
Yu Ishigami[]
Yu Ishigami is a fellow member of the student council. The two tend to have a tense relationship as they constantly call each other out on their faults (her referring to him as creepy, and him catching her cheating at games). Ishigami is often the only one who can counter Chika's more chaotic aspects while Chika enjoys teasing him whenever she's given the opportunity to.
Later, it's revealed that the two hold some fondness for each other (Chika being sympathetic to his situation and Ishigami admitting her genius capabilities). The two are shown to care for each other as friends.
Miko Iino[]
Miko Iino is a fellow member of the student council who has looked up to Chika since childhood. Chika often takes advantage of this relationship, something which Ishigami compares to an abusive romance.
Tabletop Gaming Club[]
Tabletop Gaming Club is composed of Terashima, Chika Fujiwara and Kozue Makihara. They are implied to be very good friends, but only Fujiwara is a main character so this relationship is not often displayed.
The club is infamous as troublemakers when the three girls act together.
Friends[]
Kei Shirogane[]
Kei Shirogane and Chika consider each other as BFFs, Kei sleeps over the Fujiwara's house a lot due to her connection with Moeha. Kei calls her "sis".
Ai Hayasaka[]
Ai Hayasaka and Chika Fujiwara are Kaguya Shinomiya’s closest friends and they occasionally meet and talk to each other. At school, while in her 'gal mode', Hayasaka maintains a friendly relationship with Fujiwara. Haysaca (her cross-dressing butler persona) is the only 'male' character to date who Fujiwara has shown genuine physical attraction to.
Because of the role Hayasaka played in helping Miyuki Shirogane and Kaguya Shinomiya get together, she often had to eliminate factors that may potentially have hindered the progress of their relationship. As such, she often clashed with Chika Fujiwara. Because of her 'chaotic' and unpredictable nature, Hayasaka sees Fujiwara as her nemesis, even going as far as to give her the name 'Subject F'.
During winter break, at a mall, Hayasaka was constantly pestered by Kaguya who talked about her kisses with Miyuki in excessive detail. Eventually, she became frustrated and desperate to know what a kiss actually feels like. During that time, she was also distracting Fujiwara in order to prevent her from potentially ruining Kaguya's date with Miyuki. Hayasaka asked Chika how she feels about kissing and the other girl admitted she would like to be forced into a kiss by surprise. Shortly after, Hayasaka attempted to kiss her.
After winter break, the two's relationship has become awkward and ambiguous. Fujiwara is anxious of Hayasaka trying to kiss her again, while the latter is trying to desperately explain her actions.
The two eventually become good friends, even working together to help Kaguya avoid her family's plans. In one scene, Chika even being pleasantly impressed by Ai's masculinity and confidence, extremely embarrassedly states that she won't mind if "Hayasaka kisses her, but only once", still thinking that Ai might have some kind of crush on her. Anyway, at the end of the arc, you can see that Chika stood around for almost the entire scene peeking out from behind Ai, thus showing that she trusts her enough as a friend and protector.