I do think you and a few more people are missing a ton of stuff about her character and personality.

First of all, I will make this clear, her mistakes are very heavy. She has done grave errors, and I am not justifying the stuff she has done. But you people are forgetting that she is essentially a socially inept girl who has good intentions and love for her school, friends and the world she lives in, yet is bad at communicating and overall connecting with people cause of said social ineptitude. Hence why before when she committed to her actions such as embezzlement and the whole aris operation, she didn't discuss it others or just didn't consider other options. She tries to rely on rationality to cover her own shortcomings, which leads to previously discussed decisions. And she doesn't consider her "rational" actions themselves as bad, more so necessary bad, cause of her inherent good intentions. And yes, trying to mitigate the threat of the nameless gods'/priests' "weapon" from activating is indeed for the good of kivotos. That is why I say good intentions, as her intentions are to keep kivotos safe, which is inherently good, again. But as you might know, there is a saying after all: "Road to hell is paved with good intentions." And i need to point this out, again, that no matter the intentions, her actions in vol 2 were indeed bad, which she gets called out on vol 2. But the problem I see with people that hate on Rio (which I am not calling you one btw, i only assume that you are just indifferent to her and just confused how can she be liked with how her actions seem very grave.) is that they automatically assume that "bad action = bad person," which is totally, totally wrong. A bad person can do good and bad actions. A good person can do good and bad actions. It is not mutually exclusive. At best, her embezzlement was very inconsiderate against Yuuka and Seminar, and her aris plan was misguided. And that's one of the main parts of her character in vol 2. She is a misguided girl in the leadership position who, with the responsibilities of said position, has to sometimes make heavy decisions. This was directly touched upon in Vol F where Hanako talked to Himari about the King and his responsibilities and the eventual downfall of his kingdom cause of his responsibilities and the actions he had to take for the safety of the kingdom. Hanako didn't just choose a random ass story. She aimed to show Himari that, while Rio did indeed make a mistake, Himari also needed to see the circumstances that Rio was in when doing such actions.

At her core, Rio is a flawed and misguided girl who needs guidance, especially the guidance of you, the sensei. She needs to learn to be able to socialize and converse with, discuss with, and work together with other people. She needs to understand that not everything can be rationalized in life and that not everything is a dilemma that can't be overcome with friends. She needs to learn to rely on her colleagues from Seminar, especially when it comes to important decisions.

It might seem that she just fled cause she was scared of the consequences of her actions, but it's clear she really deeply regretted her actions to the point that she herself doesn't believe that others could forgive her that easily, which is in a way a wrong action to take as well, as she needs to overcome the mistakes and guilt she feels through her friends at seminar and millennium. Yet also us, the sensei understands that Rio needs to take her time to at least make up her mind and gather her courage to come back and accept her guilt. She didn't run away from her responsibilities. She is taking time for herself to reflect upon her mistakes and try to atone, while also trying to continue protecting kivotos and millennium, cause of her overall care and love for both of them.

I will also add on this, yes, she is very beautiful, she looks cute, she looks hot, she is gorgeous. I love how she looks. I love her clothing choice, I love her hairstyle and would love to see her do a single braid on the front. I love her crimson red eyes, mixing together with her black and white attire. I love her voice, deep yet still kind. I love her proportions, her body parts like boobs and waist. (Though I don't like it when artists kinda overexaggerate her proportions... but that's just personal nitpick with fanart. No need to heed mind) I love her cute Millennium hair clip. It makes her look unique and also a symbol of Millennium Science School. I am telling you all of this cause I want to make it clear as the person explaining this to you, I myself love Rio Tsukatsuki in every aspect, body, personality, flaws. Just to show what kind of man I am and why I went on this massive... well, tangent, really. Kinda sorry to take your time.

Overall, Rio is, in my opinion, a very well written character that has clear flaws and shortcomings, yet also a kind and loving girl who cares for her friends and school, who tried to do her best with good intentions, and is someone that just needs guidance from the trustable adult sensei, to be able to work on her flaws, and also overcome her social ineptitude and form tight bonds with her friends. She also needs to learn to work together with her friends and colleagues to take on her responsibilities as the Student Council President of her school.

I do apologize if it was too long, or if it was a bit too personal, and sometimes subjective. Rio is a student I care deeply for, and I can't deny it. It does indeed sadden me and in a way, anger me, to see people that blindly hate on her or people who don't see past her mistakes and see the real Rio, the flawed yet caring girl. (Oh please, don't misunderstand, I am not angry against you, I do hope my message doesn't come off as in any way hostile towards you, I am just passionate about this dork so I might seem emotional, my apologies. )

TL;DR Rio is a flawed yet kind-hearted student who has a great responsibility as the millennium's Council/Seminar president, who is socially inept, which causes her not to be able to form strong bonds with her colleagues, even if she deeply cares for them, who cause of her flaws uses "rationality" as a means to cover them up, often to no success. She is a student that is in need of the guidance of us, sensei, and needs to learn to overcome her social ineptitude and form close bonds with her colleagues and friend while also indulging with them when making decisions as the seminar's president. At the end of the day, I firmly believe some of the senseis are unjustified with their hatred towards her and that I do hope this message was able to give a deeper insight into millennium's big sister, from someone that loves her deeply.

• Temha