|Appearance||Period 42: Best Friend Chocolate|
|Fate||Unknown - kidnapped by Chiyoko|
Hina has long wavy hair worn loose with a portion of it pulled into a side-tail held by a pair of baubles. Her bangs are thick and mostly brushed to the left and she has long forelocks. Her eyes are slanted.
Hina is a friendly girl who adores Mari to no end and treats their friendship as something special. While she is often compared to Mari, she doesn't really mind until someone questions their friendship and point out how different they are. She's easily worked up and seems to be self-conscious when comparing herself to Mari, but Mari is capable of assuring her that she likes her the way she is.
Hina made homemade chocolate and exchanged it with Mari on Valentines Day. She was delighted to see how pink and cute Mari's had looked, and Mari mentions doing this for her. But after handing out chocolate to some other girls, she grows annoyed when they teasingly begin to point out how different the duo is from each-other, and how Mari is "better" than Hina. Mari defends Hina however, and Hina happily thinks about their bond.
After school Hina hurriedly ran for home seeing what time it was and she stopped, nearly running into a strange older woman who held out a present for her. Hina, confused by the gesture found herself shaken when the woman suddenly thrust it into her hands and ran off. Uneasily she tossed the present into the nearby trash and headed home.
The following day Hina spoke with Mari about the handmade chocolate she had been dying to eat. She was annoyed though, considering her father didn't even pay hers any attention. But the subject suddenly changes when she sees the same present in her shoe-locker, and once she opens it, she runs for class in fright, leaving Mari to chase after her out of concern and wonder what happened. There Hina explains what happened when a classmate joins the girls and tells them the legend of Chiyoko-san, but Mari -aware of Hina's- alarm claims that the boys were probably just picking on her. She recalls that while she kept rejecting the chocolate, she had touched the present box twice and opened it- technically saying that it counts as acceptance.
Hina attempts to calm down, but once class starts she is further stressed out upon finding the re-wrapped gift now within her desk. She suddenly cries out, alarming the remainder of the class and the Teacher, who contacts the other staff and gets a patrol set up around the school for safety measures.
Hina initially manages to keep her wit, but she feels saddened when a group of girls she invites to come play outside avoid her. Mari assures her that she will be okay though, and she brings her outside to play as Hina wonders why she hasn't run away from her yet. As they are best friends, Mari claims it would be too hard to stay away from Hina and she begins to cry, touched by her kindness. But her joy is short-lived when they hear a commotion from other students and together they head inside to see that a Teacher has been given chocolate by Chiyoko as well, causing them all to realize that she is currently on the vicinity. Fingers are quickly pointed at Hina for causing this, but Mari defends her; only to recoil in fright as they see Chiyoko suddenly appear, standing outside of the nearby window.
She gestures for Hina to approach, but she refuses and brushes her off- full aware that it could be dangerous. She asks Mari to contact the teachers, but to her shock Mari suddenly runs away. Sadly, Hina observes her disappearing form and remains stunned throughout the remainder of school, up until the time Mari decides to leave with a few other girls from class. Hina is taken by a teacher to wait for her parents to show up, but when the teacher momentarily leaves her to get something, the disillusioned Hina is driven by rage as she overhears a discussion about how someone pities her for being abandoned by everyone due to situation. She mentally tells Mari off for being so heartless and trails after her, shoving her down the flight of stairs once the other girls have gone.
Hina runs straight for home, shaken up by what she just did but justifying it by saying that Mari was to blame and because nobody witnessed it she will be fine. She sits down at the table to wait, but grows nervous when she remembers that her parents left to pick her up at school; but it's no big deal. She decides to browse on her phone for the time being when she sees a text she got from Mari. Shocked by what she hears, Hina realizes that Mari never turned her back on her: this whole thing had been a trick to lure out Chiyoko-san. She had to pretend to abandon her in order to isolate Hina, and as much as she hates the idea she asks that she plays along and keeps by an adult whenever possible.
Hina gets up and hurriedly gets ready to leave in order to apologize to Mari, but to her alarm she finds that Chiyoko has broken through her house locks. Before Hina is able to do or say anything, Chiyoko approaches and shoves her homemade chocolate into her mouth, causing Hina to lose consciousness as she thinks about Mari.
- Hina is a lot like Ayumi Ooishi.
- Both have O surnames.
- Both of them wear their hair in the same style.
- Both are shown to be the livelier friend of the duo.
- Both admire and deeply cherish their best friend, both of whom also resemble each other.
- Both girls are made fun or teased by their classmates, who don't understand their friendship with the more popular other girl.
- Both end up snapping and turn on their friend, then doing something that leads to them being kidnapped or taken away at the end.
- She shares her surname with Haru Okamoto, the Protagonist from Period 27.
- Like Haru, she also has a 4 letter name starting with H.