The Socratic seminar table is open who wants to chime in

I can see her as both. I like to think RGU Anthy always had hypersexual tendencies but it was always used to exploit her as a rose bride, so she tried not to act on it as much. Or at all

Starting off with Satou. She was raised by her extremely mentally unwell, neglectful, hypersexual Aunt. In canon, the extant of her abuse was bringing sexually and physically abusive dangerous men into the house constantly as well as being very open about her sex life in front of her. Satou's early idealization of love was to find it in anyone who gave it to her because her aunt would do the same. The only difference is Satou's aunt was actively seeking out abusive men. Satou wasn't. But she was exposed to them her whole life. I wouldnt be surprised if the men who her Aunt invited abused Satou as a child as well. And the reason I belive this is because of Satou's early hypersexual behaviour. In the anime, she had a reputation for being someone who was promiscous with alot of guys but they seemed to be guys her age. In the manga its very clear that Satou was sleeping with way older clearly pedophilic men as a child, as young as middle school.

As seen Most often with victims of grooming and hypersexuality, they usually have a history of CSA earlier in childhood. Thats why I believe her first exposure to abuse was through her aunt's partners. Her Aunt states that she would bring men who've committed murder and even worse things into her house. I wouldn't be surprised if pedophiles seeked her out as well

Some people might argue that even though satous aunt is a horrible person, she draws lines at pedophilia. For example in a Manga exclusive scene when she meets shio, the first thing she does is check if Satou is sexually abusing her. And in the scene where she raped Taiyuo, its clear she did it because she was aware that Taiyuo was a pedophile who was trying to prey on shio

But personally that's not how I interpret her character. In the scene where Satou confronts her aunt about how the "love" she exposed her too was wrong, her aunt seems to be infantilizing her and nodding and smiling to the things she says like you would to a toddler. I don't think she's taking anything Satou says seriously. Especially in the scene where she tells her to not over step boundaries cause she's still a child who cant take responsibility for her actions and that if she want's to over step, to do it when she's a dirty adult. She knows that Satou sees the love she has for Shio as pure and not abusive, and that she hates her aunt giving her a warped perception of love and sex.  But in reality she sees that Satou has already been corrupted and is trying hard to paint their relationship as a pure one. She's entertained by the truth that Satou at this point is barely better than her and is trying so hard not to be. She's being vindictive here. 

Sure she checked on whether or not she was sexually abusing Shio, but Satou very clearly framed the relationship she had with Shio as a romantic one. She told her they were planning on getting married. So she is okay with that aspect of their relationship. She wasn't checking on her to stop Satou if she was molesting shio, She was checking on her to prove a point. Even if Satou was, her Aunt wouldn't have done anything about it and gone along with the plan of helping them elope. Because she has invited and loved men who've done worse than that into her own house constantly. That's partially the reason why Satou is disgusted when her aunt says she loves her too. She's putting Satou on equal ground with "the men who came here and did worse than killed someone".

Her aunt also clearly has pedophilic tendencies herself. Say what you will about why she raped Taiyou, at the end of the day that was a grown woman that was punishing a 15 year old boy by raping him. Normal people with standards about pedophilia don't do that. I genuinely don't think she cared that Taiyou was preying on Shio, she was looking for an excuse to prey on someone. It just happened that she was preying on someone that she instantly clocked as a pedophile and used it against him. Additionally she was also being creepy with Shoko. Satou's 16 year old friend. After she offers sex to the police officer she immediately tries to clock Shoko's problems and gives her the whole "starved of love speech" which is clearly her offering sex. Satou's immediate intervention to protect shoko solidifies this

All these signs kinda make me think that Satou's aunt could have possibly sexually abused her too. In all of Satou's memories of her aunt if she isn't being abused by her partners she's portrayed like this. Look at how terrified and repulsed she is remembering the words her Aunt said to her while currently trying to force herself on the police officer, while repeating those words

I'm thinking about how the first time Satou stands firm in her belief that "It's wrong to abuse children" is when she finds out her manager, who is an older woman around her Aunt's age who wants to hoard love to herself, has been raping Taiyou, a coworker closer to her age. Taiyou is an interesting foil to Satou considering they are both also fixated on shio being this becon of purity that heals them form their past sexual abuse. I think she saw alot of herself in him in that moment.

Satou's entire philosophy about love was tainted by how much her aunt would conflate sex and abuse with it. Satou was never around non-sexually violent love. Which is why does does the extreme opposite with Shio. She makes their relationship practically asexual and at best romantic when it needs to be. I personally believe that Satou isn't romantically attracted to shio at all. Her love for her is familial/platonic. But this is the first time in her life that she's felt this kind of love towards anyone, and because the only love she was exposed to was romantic/sexual, she assumes that's what she feels towards shio. And again the previous muddying with sexual boundries with her only blood relative is to some extant replicated with Shio. Which is why she thinks she is in love with Shio.

Shio kinda has a similar problem but not as extreme as satou does. It's more subtle.

To start off, The marriage and vows that Satou and Shio idolize? That was Shio's idea. Where did she learn that from? Her family.

Yuuna lives through an abusive marriage and as a way to comfort her children she made them do marriage vows with her. She primarily did it to Asahi, and later Asahi and his mother taught it to Shio. Now I don't think Yuuna was incestously abusing her children, But it is a bit odd that she used marriage vows of all things as a way from them to promise to protect each other.

Yuuna is interesting because she's someone who has idealized the concept of marriage and falling in love since day 1. Unfortunately for her she was forced to marry someone who raped her, so she never had anyone to say the vows to. With her parents dead and no one to support her, the only people she loved were her children. Of course she had no bad intentions, this was her way of coping with an abusive situation but she unintentionally blurred romantic and familial lines there.

Shio has spent most of her life with her mother more than anyone. And she subconciously uses her mother to model what normal relationships should look like. Yuuna was someone who isolated shio alot, and in doing so caused shio, who was already extremely dependant on her to be even more dependant. Yuuna would also take up all the resposibility of taking care of shio by herself to the point of exhaustion and shio saw that and hated it. She wanted to help but she couldnt because she was literally 8 and Yuuna wouldnt let her. This causes shio to feel like she was the reason her mother was suffering and hated that she couldnt do anything about it. Which all comes to a breaking point when Yuuna has an episode and abandons her

All of the traits I described is exactly what Satou also does to shio. I'm especially looking at Yuuna's "You have to stay pure and beautiful" line here. The only two people other than Yuuna who have said this to her are Satou and Taiyou. Satou doesnt call her this to her face but she idealizes her relationship with shio because of how pure and non sexual it is and how that gives her a sense of purpose, all while grooming her. Taiyou on the other hand explicitly says it to her face about how pure he sees her as and how he wants to molest her for this reason, because he feels that by doing so he'll be purified from his sexual abuse too. The whole purity thing imposed on shio was always used as a way for someone to control her.

But its especially because Shio had these traumatic experiances with her mother that it was normalized to her, and so she seeks it out with other people. Satou isolates her and constantly takes the entire burden of caring for shio without involving shio in anything but she also spoils her rotten in ways that Yuuna wasnt able to. Like Yuuna lived in total poverty and was barely making it. Satou isn't rich by any means but she was also willing to spend money getting shio things like desserts and stuff despite their living situation. This probably meant everything to a freshly abandoned shio. And as a way to thank her, she probably introduced the marriage vows Yuuna and Asahi taught her to Shio

But here's the thing. As far as Shio is aware, wedding vows are a very platonic familial thing. Shio is isolated, she'd have no way of knowing what the significance of actual wedding vows mean. Yk who probably does though? Satou. She's the one that tells Shio that two girls cant get married when Shio says she wants to marry her. Satou was surrounded by romantic and sexual love and I'm sure the men that groomed her at some point made marriage promises to her, as pedophiles do to children they groom sometimes, if she didn't learn that directly from her aunt. Satou is someone who idealizes eternal pure love which is what marriage typically represents. And to have that offered to her by someone who she idealizes as the one pure love in her life?

I wouldnt be surprised if Satou made the marriage vows more romantic than it intended to be, and shio went along with it cause she totally trusts Satou. And Shio probably thought it was harmless because Satou never made anything they did sexual, just vaguely romantic. Because that's what Satou assumes Shio wanted. This whole thing is just them constantly misinterpreting each others intentions.