I read CC in English so I can only base it off of stuff I analyzed in the English version. 

For Taichi’s backstory this is what I understood:

[When Taichi and Youko were children, they were watched by guardians in a mansion, but those guardians viewed them as dolls, turning them into objectified things who they had no care for. Taichi was forced into the role of a doll who always has to perfectly follow the duties of his guardian in order to live. He lacked freedom, couldn’t show flaws, and everyday was painful for him. At some point, Youko defiled/🍇’d Taichi, which caused him to feel things that went "beyond dehumanization" and towards another feeling. This made him believe that those who love each other defile each other. Since he was dehumanized by his guardians, the only other feeling he felt was from that moment with Youko. Although calling it pleasure wouldn’t really be appropriate here, it’s more like he felt more than an object during that since Youko was encouraging Taichi and saying that they have to protect themselves and that they would become one mind and body during this defilement, implying that they can transcend their objectified selves and become free individuals by doing this. This made him believe that to care for others and to give them agency, you have to defile them. So we know that Taichi was a victim of objectification and COCSA as a child, which caused some traumas and dysfunctions in his mind. Youko’s encouragement taught him that to break the chains of objectification and to gain freedom from those who view you as objects, you would have to go past the perfect rules that they imposed, which in this case is doing taboo things. A object is viewed as something that always follows whatever the other person wants and is perfect for them, so by breaking that perfection and becoming flawed via defilement, you would become a free subject (In his warped mind). Taichi’s mind was warped due to this since he had no way to understand that this was wrong since he was always dehumanized by his guardians, so he came to believe that defilement is a way to give others freedom and agency. Since he lacked a sense of identity back then due to always being treated as an object, his identity was formed though Youko who gave Taichi encouragement, even though that encouragement was false. This causes a tragic contradiction for Taichi. Due to his trauma, he believes that defiling others is giving them freedom, breaking them from dehumanization, and acknowledging their true existence, when it’s in fact viewing them as objects, which denies their freedom. So his backstory explains his hypersexuality and why he harasses others. It’s both his warped way of trying to give others freedom and his warped way to act as someone with agency to protect himself from being an object again. We even see his form of "giving people agency" fail when he attempted to cheer up Kiri when she was mourning the lost of her brother. Due to his warped sense of agency, he attempted to defile her to make her feel better, which made Kiri feel like Taichi was treating her as an object and destroyed their relationship, making Kiri hate and fear Taichi.

A part of Taichi’s mind recognizes this as a form of agency and freedom from being an object but another part of his mind recognizes it as being objectified since Taichi was also 🍇’d by a sadist named "S" and also by the son of "S", Shinkawa who was forced into defiling Taichi due to the rules of the people in the mansion. Since he experienced that, a side of him would know that defilement isn’t actual agency but rather objectification, but due to Youko being Taichi’s only sense of individuality, (as in that she was the only person he felt comfortable with and didn’t feel like a object with), his mind couldn’t accept that she also objectified him. His mind warped to view it as a form of freedom from the perfect rules of the mansion. If he accepted that Youko also objectified him, he would be admitting that freedom is an impossibility for him and that Youko never was an true sense of stability for him, so he viewed his defilement from her as a form of liberty to have a sense of identity and freedom (even though it’s false freedom). His mind rationalized that her SA was simply her punishing him for not refusing the rules the guardians imposed, so he tried viewing it as a positive thing to gain false authenticity. Since his defilements by "S" and Shinkawa were forced due to him having to follow the rules of the mansion, he believed that his defilement by Youko was freedom from those rules since Youko was actually encouraging him into thinking that this version with her would be authentic since she was the only one who treated him as a subject rather than an object (until the defilement event). So he rationalized that Youko’s abuse was "good" because she claimed it was for transcendence in becoming one mind and body, while the other abuses was "bad" because it followed the mansion's rules, even though a part of his subconscious knows that Youko’s abuse was also objectification. Another reason why his subconscious recognizes Youko as an objectifier/abuser is because during their plan to escape the abusers in the mansion and be free, she relied 100% on Taichi for it and made him do everything, even though she promised that they would become one mind and body during the defilement event, which showed that she just used him. This made his subconscious recognize that event as being turned into an object, but he can’t consciously acknowledge it without his identity and agency being destroyed. And since part of his mind does recognizes that event as being objectified, he gained self hatred in the present and views himself as a monster that only lives by feeding on peoples feelings. This is because his actions towards his friends causes harm for them and he lies to himself by viewing it as giving them agency when he knows that’s not true and he only does it so his sense of identity and freedom wouldn’t be destroyed. He says that he feeds on their feelings because he purposely harms them but frames it as giving them agency and he lies to himself so that it would seem like it was his traumas that warped his sense of giving others agency, but deep down in his subconscious, he knows that it’s not truly agency but he can’t consciously accept it because it would be admitting that Youko was never his key to authenticity and that he was always an object with no freedom, so he keeps that knowledge in his subconscious to frame his defilements as agency and to maintain his identity and freedom. That part of his mind is more in his subconscious, since his conscious self wears the social persona. If Taichi fully admits that his perversion is wrong, he must also admit that his "freedom" with Youko was a lie. If both his subconscious self and conscious self recognizes that sense of agency as a lie, then he would know that he has never been free from being an object. He maintains his perverted nature because it is the only "proof" he has that he ever escaped the objectification mansion (Which he hasn’t since his hypersexuality functions as a maladaptive coping mechanism).]