Hina Tachibana (橘 陽菜, Tachibana Hina), is one of the main female protagonists of the series. She is the elder sister of Rui Tachibana, and after Tsukiko Tachibana (Hina's divorced mother) marries a widower named Akihito Fujii, Hina becomes the stepsister of Natsuo Fujii.
Hina is a young woman with waist-length dark brown hair that has trimmed bangs which are parted above her right eye, emerald eyes, she is described to be well endowed with a voluptuous figure where men are unable to take their eyes off of her when she's in swimwear. Her natural beauty combined with her friendly personality has made her an outcast in high school due to the jealousy of female classmates.
As an adult, she dresses professionally at her workplaces. During casual settings, she often wears fashionable clothing that compliment her figure.
Hina is a gentle and pure-hearted young woman whose cheerful attitude mixed with her naiveness gives her an aura of tenderness impossible to go unnoticed, even though she is a little bit clumsy and helpless at cooking. That actually caused her some distress back in her second year of high school, when her female friends out of jealousy decided to shun her. That was the time back then when she met a third year Biology teacher named Shū Hagiwara, who after noticing she was crying while eating left alone in the science lab, used a hand puppet and a trick on ventriloquy to take her out of her sadness. It turned out that she became a regular there, until the teacher left the school by the end of that year. That experience might have pushed her into pursuing the career of teaching. It is also pretty much likely that due to a necessity of a paternal figure added to the kindness of Shū, she developed a crush on him, which led her to get involved into an affair with him time after they ran into each other as she was in her fourth year at the university.
It is not so clear if she feels becoming a teacher is her true call, even though she admits she has worked really hard to get her license. Anyway, she is very committed to her students. At both schools she worked, she was praised for the increase in the grades of her students. Not only she kindly encouraged them to keep on studying, but she was understanding, and even met them outside to provide counseling on any matter. In fact, it is clearly stated more than once that all of her students were fond of her as a teacher.
On a more personal insight, it is noticeable she has that of her father's personality, in her sense of even going to a stoical behavior in order to avoid troubling others as well as to protect them from any harm, even by putting them aside or better putting herself out, for which she usually bottles up her true feelings. That could be evidenced since the very first chapter, when we learn that she is used to escaping during the breaks to the roof of the school, to cry alone when something is conflicting her — which in turn, leads her to cross paths with Natsuo Fujii, who ends up cheering her up or at least truly trying to.
This way of being has put her through two major conflicting situations to note. The first one is when she realized she was trapped in a worthless affair with the man that she used to admire back from high school, Shū - she told Natsuo she had been struggling for six months not knowing how to put an end to that relationship, until she was confronted by Rui and him, after which she could come up with a resolution. The second one is when she tries to discretely handle the increasing harassment of Kengo Tanabe, until his former fiance opened her eyes and finally recurred to the police for assistance. Moreover, believing that was enough to settle things, she let her guard down, putting herself at the stake, because he chased her a week later with the intention of stabbing her.
Even though most of the time she's a well behaved young adult, she also has this childish side - sometimes playful, sometimes stubborn - that maybe develops under the influence of herself wanting to be as young as to be with Natsuo. Thus, on chapter 33 for example, we can see how she bites Natsuo's hand out of anger and desperation on avoiding confronting him, and when rebuked by the Master of the Café-Bar, she wouldn't calm down until given a lollipop (which ended up showing her most tender inner side).
She is really into comedy shows. She definitely enjoys watching them on TV and going to live skits for amateurs from time to time, too - even to the point of greeting them after the performance. She does enjoy festivals in general, not only for the food but for the different attractions - especially the goldfish scooping. She also likes to go to Ramen Shops for which she usually treats Natsuo, so that he goes along with her.
She is afraid of cockroaches to the point of running away from seeing them, without worrying if she is wearing something or not. She also freezes up with thunder storms. As a child, she endured it for she thought she had to comfort her little sister, but she was terrified as well, especially if they were home alone. And after the incident with Kengo, she seemingly has gotten affected, starting to tremble at the minimum happening of a sudden and unrecognized noise.
Hina starts by being the English teacher and unnoticed crush of Natsuo Fujii. By the time she meets him, Hina is 22 years old, and has been in an unworthy relationship for almost two years with Shū Hagiwara (Hina's former high school teacher and first crush) who is already a married man. Seemingly affected by that fact and the progressively increasing disappointment of being in such a relationship, she has become affectionate to drinking since her last year at university.
While at work, she uses her breaks to go to the rooftop to discharge her feelings. It is there where she becomes acquaintance with Natsuo and because of his resolution for life, she starts admiring him, growing in fondness towards him as time passes by. It is due to all his sincere care and attention that she starts questioning her current affair, as well as growing feelings for Natsuo.
When she gets aware of that, she tries to discourage him up to three times, until she finally gives in to what she feels, thus devoting herself to support Natsuo to the fullest, trying the hardest to overcome her own flaws and even putting herself out for his sake.
Rui is Hina's younger sister. Growing up, they were quite close and relied on each other a lot. Both of them are afraid of thunderstorms; in their younger years, Hina would be the strong one and comfort Rui in her arms. Although Hina secretly envies Rui for her ability to be herself and go after what she wants, Rui also secretly envies Hina for her warm personality and ability to make friends easily. Hina's well developed figure is also a source of insecurity for Rui.
While Hina was having an affair with Shū Hagiwara, Rui and Natsuo Fujii intervened in an attempt to break it up. Although they failed, the relationship ended regardless with Hina being the one terminating it. Not long after that, both sisters become entangled with their feelings for Natsuo. Though Natsuo has known and had feelings for Hina for much longer, Rui was the first to take his virginity, which is still unknown to Hina. Nevertheless, Hina eventually relents to Natsuo's affections and eventually returns them, which strains her relationship with Rui at first, but they eventually patch things up.
Unfortunately, Hina's relationship with Natsuo is discovered at school, which leads to them to break up and this leads Rui to try again at Natsuo's affections, in which she eventually wins. Hina is initially unaware of this until Rui breaks the news to her and Hina is uneasy about the relationship at first due to what Tsukiko Tachibana (Hina's mother) would think, but she supports them nonetheless as a big sister figure even as she represses (subdue (someone or something) by force) her romantic feelings for Natsuo.
- The name Hina means "light, sun, male" (陽) (hi) and "vegetables, greens" (菜) (na).
- Hina's surname Tachibana means "orange, tangerine" (橘).
- Volume 1: Chapter 4 (p. 13)
- Volume 2: Chapter 14 (p. 9)
- Volume 20: Chapter 185 (p. 11)
- Volume 14: Chapter 132 (p. 14)
- Volume 7: Chapter 63 (p. 3)
- Volume 11: Chapter 97 (p. 9)
- Volume 1: Chapter 2 (p. 29)
- Volume 2: Chapter 8 (p. 6)
- Volume 18: Chapter 171 (p. 3)
- Volume 19: Chapter 180 (p. 1)
- Volume 3: Chapter 22 (p. 18)
- Volume 17: Chapter 155 (p. 6)
- Volume 21: Chapter 201 (p. 15)