I do think Honoka would be quite impressed by Kaguya's quirk, because it's really cool just by default. And she's the sort to get excited about that sort of thing. I'm not sure how much of a mecha fan Honoka is, but I definitely get the references and that's pretty fun, too.
From class A, I'm primarily looking for a rival, since I'm going off the assumption that the few times class A and B have had an opportunity to interact, it would have been in a competitive environment. Honoka is a good candidate for a rival, since Kaguya would for sure take interest in someone who could effortlessly stop one of her signature rocket punches. However, I think Kaguya would prefer a rival with a slightly more abrasive personality, since she would thrive on their mutual desire to constantly one-up each other. I may have failed to mention Kaguya's primary fault; she assumes that every one of her peers is capable, and she therefore expects nothing but their best, which tends to make her blind to individual weaknesses. Her hyper-positivity and can-do attitude can come off as condescending because she won't accept excuses, even if those excuses are valid. She doesn't believe in handicaps, and tends towards recklessness, even in simple training exercises, which can lead to dangerous conditions and a general disregard for safety. She thinks everyone is as tough or as smart as she is, and her inability to come to terms with her disappointment can cause her to exude an oppressive, almost slave-driving pressure to her peers as she continues to encourage them far past their limits. I don't think this is going to be an issue between Kaguya and Honoka, but I thought I should mention it.
I think that Kira and @The Ghost Note's Tropica would go along well OR with @sly13's Todoroki, mainly due to their tempers.
But could also enjoy working with @Lord Indra's Sasuke as she'd want to learn how to fight at close range from him.
I can see Kira and Kaguya being an unhealthy duo. Like I mentioned above, Kaguya not only feels invincible, she assumes her peers are as well, and likes to encourage others to live their 'best life'. If Kira has a tendency to act out or behave irrationally, there is the possibility that Kaguya might join in or encourage such behavior, without realizing that said behavior might be harmful to Kira or those around her, until its too late. Still, going overboard once or twice resulting in negative consequences might be a cause for self-reflection and bonding through mutual shared pain.
Also, upon which part of the body do Kira's black and white auras work, the brain? The heart? If one of those two, then Kaguya's rocket fists would probably create a bit of a loophole since Kaguya's fists could be inside the aura, but her brain and heart might be outside, thus leaving her unaffected. Just a thought.
Tropica is interesting. Depending on how ambitious Phoebe is for fame, Kaguya, who is already an up-and-coming youtube star, might be able to offer some pointers. Of course, Kaguya revels in the attention, which partially validates Phoebe's world view, but if a fight with a villain results in collateral damage to a hospital, for example, Kaguya will organize an impromptu charity event immediately after the fight, asking her viewers to donate generously. Kaguya can flawlessly weave altruism into her hero work, and might be able to show Phoebe that the two are not mutually exclusive.
Hasaki is probably a good candidate for Kaguya's class B rival; if she sees someone arrogant, she'll assume that they have the skill and/or power to back it up, and she'll see such a person as someone she can test her mettle against. She also knows that such people are probably easy to goad into giving their all, allowing them to build off of each other endlessly.
I haven't decided on what martial art for Kaguya to focus on, but incorporating one will definitely make her a lot stronger. Discussing her options with Sasuke is probably a great way for them to become friends. She also doesn't look down on him for being quirkless, since she believes if the school accepted him, then he must be good enough to fight those with quirks. That being said, if Sasuke challenged someone to a 'quirkless fight', Kaguya would encourage the opponent to use their quirk since she believes Sasuke is capable of dealing with it; which could potentially endanger Sasuke's wellbeing.
My character is Yukimura Shinon:
-Musically Talented in singing and using instruments; Harps and Flutes
-Keeps herself Organized
-Intelligent
-Follows the Guiding Principle of her mother
-Super girly (mostly wears dresses)
-Embarrassed frequently
-Switch Personality (kind, sweet, bubbly, shy or aggressive, competitive, serious)
-A Perfect Model Student @ Eirei (Perfect Attendance, Follows instructions to the letter, etc.)
-Watches Anime in the limited free time she gives herself, every genre, but she only has enough time to watch a single episode.
-Himura DNA inside of her to keep her looking young
Her Quirk is Tidal Wave. Her family is the Yukimura Family, a well-known family, who are retainers to the Himura Family. Also, The Guiding Water Hero: Glaser is Shinon's Mother, the Number 8th Hero.
I think Shinon would praise Kaguya's quirk as impressively cool. All because she follows her mother's principles of guiding others. It is better to use positive connotations when describing other's quirks. Shinon does understand the concept that Kaguya is going for. She's not a hardcore mecha fan like Kaguya, but she can understand where the concept comes from. It's a bit funny, but she hasn't ever played a video game before and would be lost in trying to play any of them.
As someone from class A, Shinon and Kaguya's interactions would probably be limited to a handful of competitive events. However, if like a traditional Japanese School, Eirei publicizes test resutls and grades, the Kaguya and Shinon would probably recognize each others names, as I can see them both topping the lists. She may look and behave like a delinquent, but academically, Kaguya's no slouch. Actually, I can see a classic, tropish, genius vs hard work dichotomy, since Kaguya is a 'genius' in that things come easily to her, so maybe someone who gains high scores through hard work, study, and effort overcoming Kaguya as an obstacle would make for a good scholastic rivalry that becomes mutual respect. I don't know if Shinon has a complex about the Himura's, but if she did, Kaguya's just the type of person to teach someone not to live in someone else's shadow, since Kaguya doesn't believe that 'where you come from' defines who you are.
I’ll throw my hat in here about Yozoru
* Has a vested interest in Astronomy as a result of being born with a star in her chest
* Trustworthy
* Respectable grades when it comes to STEM related things (naturally) like space and Astro-tech
*Primary personality traits include emotional intensity, do or die attitude, extroversion and sympathy
*Wears revealing things like fishnets, crop tops and ball shorts because her body doesn’t handle heat well, due to her quirk raising her temperature to a fever temp normally, (she’s used to this of course) basically she always dresses like she’s in Arizona during the summer
*Not exactly well organized, knows where things are but only casually
*huuuuuge lesbian (space is a lesbian, it’s not called a gal-axy for nothing)
*Very proud of herself physically, and treats her body like a temple, because she is the god to which it is devoted. After all, not everyone has neon-violet glowing hair and hydrogen-blue glowing eyes
As a rocketman, it is Kaguya's purpose to "reach for the stars". Kaguya will find Yozoru's quirk incredibly interesting, while also respecting its sheer power. Yozoru's probably a good candidate for Kaguya's Class A rival, since they have some interesting quirk parallels. Even though I mentioned above that Kaguya might look for a rival with a more abrasive personality, this matchup is hard to pass up. They can also share in their love of the sciences and visit a planetarium together.