Bluntness Yuyuka’s true self beneath the façade is someone with quite a temper, who doesn’t hesitate to speak her mind and doesn’t sugarcoat her words. She’s well aware of her sharp tongue and describes this part of her personality as nasty. Though she can effortlessly put on an act, in her natural state, she doesn’t bother to cover the emotions that show easily in her face, especially when she’s displeased or unenthusiastic about someone or something — which is very often the case, as she’s an easily annoyed (especially in the mornings!), somewhat impatient and grumpy person.
Dignity I perceive Yuyuka as someone who, in many ways, values poise and self-respect highly, and attaches great weight to appearances. This is different from pride and control (discussed below), albeit closely linked, and in some aspects related to her bluntness as well as her qualities as a friend. Think about it: Her very first line in the story is in reponse to other students gossiping about the new transfer student; what she says then is not a step in her plan to flatter or deceive Suzume since they weren’t acquainted yet and Suzume wasn’t friends with Mamura yet (Yuyuka’s motive for approaching Suzume later on). The way she delivers that line and her facial expression are also not presented as part of her cute persona: Asking others not to speak ill of someone they barely know is, of course, the nice thing to do, but in that particular scene, everyone is doing it, which means Yuyuka is going against the flow — her persona, however, was erected to avoid conflict in the first place.
Whether or not you factor in her mask, that first impression is easily explained with something that is portrayed repeatedly in the series: Yuyuka, at her core, is someone who dislikes excessive and shameless behaviour and lack of etiquette. She considers students who openly fawn and gather around another student an eyesore (for example when the reveal of her true personality earns her a lot of admirers, and when Mamura turns out to be popular among new students later on). What’s more, she’s constantly nagging at Suzume about a plethora of things concerning her appearance: talking while eating, eating too slowly, eating with her hands, stuffing her mouth too much (isn’t it lovely how you learn what Suzume enjoys doing just by reading what Yuyuka gets annoyed at?), arriving at school sweating due to running, standing around dazed in the morning and blocking the way, coming to school with a “horrible” face (e.g. eye circles due to lack of sleep), and so on.
In many instances, Yuyuka’s own dignity is linked to her pride: When she is caught fighting with Suzume and on the verge of being found out by Mamura, her crush, she fully expects Suzume to tell the truth — but rather than making excuses or lies, she lowers her head in defeat and remains silent, even with tears about to run down her face. The shock may have contributed to her being speechless, but although Yuyuka is a cunning and very clever person, she’s not a habitual liar, and though she hates losing she accepts defeat gracefully. When the class goes on a field trip, Yuyuka chooses the fishing activity in order to be in the same group as Mamura — even though she knows nothing about fishing. Once there, she freezes in disgust as she sees the box of baits, but does not ask Suzume (someone who loves fish and is used to fishing) for help until the girl notices and forces her to accept it under much protest, as Yuyuka was still determined to see the self-chosen activity through.
Similarly, Yuyuka is easily embarrassed when people, namely Suzume, openly show affection for her (being thanked, hugged, or witnessing someone else being happy for her), and usually responds to it in a rather cold, seemingly uncaring and even annoyed manner — not that Suzume minds, since she understands Yuyuka so well.
Pride Yuyuka’s defining characteristic, to me, is her pride. It colours the way she carries herself, the way she interacts with others and even the way she speaks in certain situations. Her character arc is about starting to be honest; this, however, is not honesty towards herself (which is directed inwards), as she already is a very introspective person who has a good grasp on her own personality — it’s outward honesty that she lacks: the courage to show her most intimate feelings openly without being held back by pride or concerns of dignity. This is not to be confused with matters that aren’t dear to her, as Yuyuka has no trouble voicing her opinion on everything else.
On a superficial level, her pride shows in the fact that she severely dislikes losing. One of the few instances where her pride is referred to as such is in the aforementioned scenario of new students enthusiastically chatting up the suddenly popular Mamura, a behaviour that annoys Yuyuka not just due to its shamelessness, but because she herself “couldn’t even win his love”. More accurately, I think she remembers the many times she tried to make conversation with him only to have it end abruptly and awkwardly every single time (which is not solely her fault, since Mamura, too, changes over the manga to be kinder around girls). A different interpretation of the line brings forth the side of Yuyuka’s that can’t stand being looked down at (even indirectly) and can’t imagine anyone succeeding where she has failed.
The way her pride affects her communication is first seen when she truly becomes Suzume’s friend: It must have been a huge relief and surprise that Suzume not only kept Yuyuka’s true personality to herself rather than paying her back for what she did by giving it away, but went as far as covering for the person who has just fought with her. Instead of showing how touched she is and thanking Suzume in a straightforward manner, Yuyuka turns her back to her and walks away, accepting her friendship while affectionately “insulting” her and pretending to brush it off as a relationship with benefits. During a field trip, she worries about Suzume’s absence and is unable to rest until her friend has returned, but vehemently denies such motives when her teacher teases her about it. She turns her back to Suzume again when Suzume thanks her for all her help and for having waited for her. (Compare this to the bashfulness in response to signs of affection mentioned above.)
That side of her pride isn’t so much of an issue around people like Suzume who truly understand her and are able to interpret her messages correctly, but against the unknown and in matters of the heart, her pride is a hindrance. As another character who easily sees through Yuyuka later points out, she is a person incapable of voicing her feelings to her crush, Mamura, due to her pride, so she doesn’t even seriously attempt it. Once she has made up her mind to do so, however, she struggles to get any words out, then decides to break the tension by saying that “a friend of hers” — rather than herself, the speaker — has liked Mamura for a long time, which is promptly met with a “I might sound mean, but I don’t like girls who ask their friends to confess for them.”
During a school play, Yuyuka states in a private conversation that she has confidence in her acting — in response to a compliment she receives for playing her part on the stage convincingly even though she was crying shortly before the play started. I read that statement not just as her pride in her skills for the play, but in connection with the mask she wore for so long prior to meeting Suzume, enduring the emotional isolation that came with it. See, Yuyuka is the kind of person who tends to internalize her problems, hide her own hurt and try to resolve the chaos inside her by herself, rather than leaning on anyone. This holds true even after she has shed her mask, and is sadly not explicitly addressed in the manga (though Suzume acknowledges it once). I assume part of it to be due to her pride, part of it the confidence that she can solve everything by herself — and part of it may just be the aftereffect of having only herself to turn to for so long that she doesn’t realize it’s no longer the case. It’s ironic, really, that the manga doesn’t pursue this issue when Yuyuka herself tells Suzume as early as in volume two that she ought to confide in others more readily.
Control Yuyuka is a person brimming with self-confidence, and though she has moments where she expresses severe frustration with her own personality, I would not describe her as an insecure person. Still, I view her as someone with a great need to be in control (hence the shrine name), which manifests in several aspects of her behaviour already addressed under Dignity and Pride.
When I say that Yuyuka dislikes losing, I don’t just mean losing to other people, but also the loss of control: She has trouble with situations that could go either way whether she likes the outcome or not, so she either manipulates people by pretending to be a harmless and nice person so as to bring about the result that she wishes for or is comfortable with, ends conversations prematurely and one-sidedly by shutting them down with harsh words, walking away or keeping them shallow (all of which have already been mentioned), or avoids the situation altogether. She does, for example, carry a picture of Mamura around and watch him from afar, and when Suzume steps into the picture, she considers him “hers” in a way because she felt for him “first”, but doesn’t ever go all-out and make her feelings known until much later (and even then, it is mostly a response to being provoked by another character). That makes a strong point for the fear of rejection.
From the translations I have read, it’s not clear beyond doubt to me whether Yuyuka’s overly friendly personality is what she genuinely was like before she became cynical, or whether it’s fake in its entirety, set up as self-protection. Either way, Yuyuka used to be very popular among others, especially with the male gender — something that caused her to be misunderstood (along the lines of being a boyfriend snatcher), which displeases her immensely. I read Yuyuka valuing appearances so highly as the other side of her fixation on controlling other people’s perception of her due to her past experiences: Rather than showing her true self and be misunderstood, she’d rather just serve people a shallow persona from the beginning. In regard to controlling the way she is received, she’s also a perfectionist: When Suzume randomly calls out to Mamura while Yuyuka is standing next to her, Yuyuka strongly reacts with: “The next time you call out to someone, do so when I’m ready!” When she meets up with her friends in public and Mamura happens to join, she fusses about not being at her best (in referral to her clothes and hair).
Insight At school, Yuyuka is among the top 15 students of her year and regularly receives high grades on her exams, but academic smarts aren’t the only kind of intelligence she possesses. As a naturally observant and sharp person, Yuyuka is particularly sensitive when it comes to her friends. She intuitively points out the familiarity between Suzume and Shishio (since those two run into each other outside of school), picks up on Suzume’s feelings for him early on even before Suzume really understands their extent, and easily knows when her friend is hiding or worrying about something without needing any vocal cue. She also picks up on Suzume’s habit of squeezing the straps of her bag when troubled, something the girl herself wasn’t even aware of.
Her insight not just extends to the people she cares about, but also applies to herself: Yuyuka, perhaps more than any other major character in the series, is the one most in touch with her own feelings, though she is also her own worst critic.
Devotion Although Yuyuka is reserved with her expressions of affection and often looms in the background with a grumpy expression, once she has taken someone into her heart, she remains fully devoted to them, not shying any effort and being quite generous with her own time and resources, often taking the initiative even if it may be perceived as being pushy. When both Suzume and Mamura go missing during the field trip and other students are giggling about it, Yuyuka, perhaps for the first time (not counting her introduction), drops her carefully maintained persona and tells them off quite harshly (which results in her true personality being revealed to the school, though it also leads to her gaining new popularity). Part of it may have been motivated by her worries regarding Suzume and Mamura possibly being alone together, but it’s safe to say that far more than that, she’s worried about the new and first genuine friend she has made in a long time. This is also apparent in how she stays behind in the common room to wait for Suzume’s safe return when everyone is supposed to be in their rooms, and how she patiently waits for Suzume to wake up afterwards.
At school, Yuyuka worries about Suzume’s grades more than Suzume does herself, and readily explains class material to her repeatedly. Her constant nagging is to be interpreted as a sign of affection, since she has no qualms about ignoring people not of interest to her. In matters of fashion, Yuyuka is more than happy to help Suzume out with her aesthetic sense, and “prepares” her friend accordingly several times by picking outfits, applying make-up or doing her hair for her, whether it’s for something as minor as taking pictures to send home or for something as important as a date. Though she says “In exchange, you have to put in a good word for me with Mamura-kun.” at first, or tells Suzume to be more fashion-conscious around her, I doubt someone would go to such extents if they didn’t genuinely enjoy taking care of their friend and doing something nice for them.
In the context of shoujo manga, it’s also important to note that make-overs in Daytime Shooting Star are not permanent (precisely because it is sadly not the case in all manga of the genre): A plain girl is not forced by the narrative to change her looks to gain value or self-appreciation, or encouraged to maintain that look for the sake of other people’s enjoyment. Dressing up occasionally is fine as such, and is celebrated not as something solely or primarily for the pursuit of romantic love and to be desirable, but as something to enjoy with one’s friends, seeing how that is the first context in which Yuyuka “transforms” Suzume. As an aside, the mangaka even stresses that it is more natural for Suzume, unlike for example Yuyuka, to be without make-up — because that just happens to be how Suzume feels most comfortable (which needn’t mean that she’s opposed to make-up as such).
Yuyuka pays attention to Suzume during class, and routinely checks up on her friend and her love life not just out of curiosity, but to assess her progress in case she needs help, which becomes especially relevant in cases where Suzume is hesitant about confiding in her friend out of consideration. Generally, Yuyuka can get quite impatient when people are dense, which holds true for Suzume, but she always hears her friend out and assures her that it’s fine to be more self-conscious and to hope for more. She encourages Suzume in her plans and gives her advice in an energetic, fierce and thorough manner, which shows her own emotional investment in her friend’s happiness. As the one closest to Suzume, she is also the one to compliment her on her growth — but also the one to point out doubts or ill-placed hesitation. Yuyuka may be a good listener and adviser, but it’s just as important to her that her friend really thinks for herself.
As for matters of love and emotional well-being, Yuyuka goes out of the way for Suzume: When Suzume is in love with Shishio, Yuyuka creates opportunities for them to talk at school. When Suzume plans to visit the aquarium with Shishio and a group of friends, Yuyuka tricks her by agreeing to come along and offering to invite the rest (while shopping with Suzume to make sure she’ll be pretty on what will turn out to be a date!) only to ditch her last minute (with no intention to have anyone else come along from the start) so that Suzume would get some alone time with the one she likes. When Suzume is heartbroken and retreats to the countryside with her phone switched off, Yuyuka is among the friends who visit her to make sure she’s alright (even though on the outside, Yuyuka’s annoyance outweigh her worry).
An even deeper look into Yuyuka’s role and her relationship with Suzume can be found under Weight.