Chinami Oka is a female student at the university and a member of the Film Club. Her favorite hobby is to film everyone with her camera, which she calls it the "Okamera".
Chinami is a petite pale-skinned girl with pretty, long salmon hair that goes just below her waist and large blue eyes. She is fairly skinny and short in height. She also has pretty red cheeks and is always seen blushing. In Episode 19, she chose to cut her hair short, possibly to look more like Linda's hair. Chinami is seen wearing a long green shirt and big, blue, puffy pants with red to brown socks with brown shoes.
Chinami is a very kind-hearted, caring, friendly and smiley girl who also has a childish behavior for a college student (and she looks like one as well). She is always happy to get new friends and doesn't really get mad so easily. For example, when Koko Kaga got mad at her because she was hanging out with Mitsuo Yanagisawa and said really mean things, instead of getting mad at her, Chinami started crying which shows how she doesn't get angry easily, and it also shows how sensitive she is. Chinami is very popular because she is sweet and open to people. Though, it is revealed that she likes to keep her personal feelings of love to herself.
Chinami is a freshman law student at Banri Tada's university. She shares the same required English class as Mitsuo Yanagisawa and she is also a member of the film club. She appears to 'collect' good-looking people, as she wants to become friends with them, because, as she tells Banri, "Looking at pretty people makes me happy!". Chinami is a very caring person, who is always looking out for other people, even if she doesn't know them. She makes her first appearance in Episode 1 of the anime series when Mitsuo takes off with Kōko Kaga in pursuit. In Mitsuo's efforts to run from Koko, he scatters Banri's work notes across the floor. When Banri goes to gather them up from the floor, Chinami offers to help, instantly reflecting her kind heart.
Early on in the series, Kōko develops a strong dislike for Chinami after she is seen talking with Mitsuo (or 'cheating', as Kōko puts it). This dislike for Chinami is worsened when Mitsuo tells Kōko that they can never be together, and also when Mitsuo announces that he will confess to Chinami that he loves her. Despite all the verbal abuse Kōko fires at Chinami, she still remains smiley and friendly, still hopeful that she and Kōko can be friends. Later on, the relationship between Chinami and Kōko is patched up, and they gradually make their way to becoming best friends.
When Mitsuo confesses his love for Chinami in front of everyone to prove a point to Kōko, Chinami's reply is simply, "What? Don't be stupid". It's later explained that Chinami didn't understand Mitsuo's proper confession, especially as Mitsuo blurted it out in order prove a point to Kōko. Despite Mitsuo's efforts to avoid Chinami out of pure embarrassment and after feeling humiliated, she wants to be friends again and forget what happened. The group end up going to a theme park together, and there, the friendship between Chinami and Mitsuo is fixed. Chinami doesn't realize exactly how she feels about Mitsuo until she discovers that he is romantically interested in Linda. From that point on, Chinami begins to act differently and quite out-of-character, especially around Mitsuo. On their car journey to the beach, Chinami acts quite 'standoffish' (as Mitsuo puts it) towards Mitsuo when he asks about her troubles with moving to a new apartment. She plays it off as nothing big, acting like she doesn't know what he's talking about, and after Mitsuo confusedly continues to ask about it, Chinami's reply is, "Oh! I didn't think it was anything worth telling you".
In Episode 19, Chinami even has her hair cut short, possibly in an effort to be more like Linda, as Chinami does not want to lose Mitsuo to Linda. For the first time, we see an angry Chinami, when she stumbles upon Banri. To Banri's bewilderment, she waits then scolds him, acting completely out of character. When Banri says, "Don't you think you're acting a little weird? There's no reason for you to be so upset", which only makes Chinami angrier, hinting at her underlying feelings for Mitsuo. With fury in her eyes, Chinami stands up ready to walk off, her only words left for Banri being, "You're the worst!".
When Chinami arrives early at Banri's place when she's invited for dinner, she tells Banri that when she saw him and Linda hanging out, she wasn't upset; she was thinking, "Yes! Now Mitsuo won't love Linda anymore!". She tells Banri that she loves Mitsuo. She realized that she doesn't want Mitsuo to with someone else. Chinami then tells Banri that she regretted cutting her hair, after having it so long for her entire life.
- "Looking at pretty people makes me happy!" - Chinami talking to Banri Tada about Mitsuo Yanagisawa and Kōko Kaga
- "I guess she's a little unusual." - Banri's first thoughts when meeting Chinami
- "Oh, don't call me 'Oka-san', that's what people call my mom." - Chinami to Banri on the Film Club's welcoming party
- "Ah... youth." - Chinami on the shaky relationship between Mitsuo and Kōko
- "Don't be stupid" - Chinami to Mitsuo after his confession at a party (In Episode 6)
- "You're the worst!" - Chinami to Banri after defending Mitsuo when she gets the wrong idea upon stumbling across Linda and Banri talking alone (In Episode 19)
- Chinami has a hobby of filming and making videos using her own camera, due to the fact that she is one of the members at the film club, naming her own camera as "Okamera", a portmanteau name from both her own name (Oka) and her camera (-mera).
- Chinami is seemingly the only character that changes her hair on quite a regular basis. Her usual hairstyle is naturally long over her shoulders and back, with her signature fringe and bangs. She has also had it up in a double bun (still with her fringe), and when the group go to the beach, she has it in loose twin ponytails forwards over her shoulders.
- Despite Kōko's denial that she and Chinami are friends, it's suggested that they are in fact best friends, after Kōko helps Chinami with moving, tries on swimsuits with her, and stays overnight (like a sleepover).
- In Episode 19, Chinami cuts her hair short, which could indicate that she tried to make her hair more like Linda's short hairstyle, as this is what Chinami believes that Mitsuo Yanagisawa would like but she later regrets the decision of cutting her hair.