Quite frankly, this is the biggest plot in Fruits Basket; this plot twist shifted my thinking about FruBa’s genre in anime, and I began questioning who the hero/villain truly are. The beauty of this plot is that it is so human and relatable for an anime hinged on the Sohma curse (fantasy): here are two lovers and their messy adult relationship and mutual cheating. And this was so subtle and foreshadowed from the beginning.

• Two moments of Shigure to define him: 1) the dream of the zodiac god and how he took it, 2) being cheated on by Akito with Kureno—a revelation to himself how strong his selfish & possessive love is for Akito, greater than the zodiac love for the god
• Shigure’s take on the dream as more of an attachment to the zodiac god rather than a romantic one with Akito; chasing a “beautiful feeling” and trying to make those feelings real/his own (the beautiful feeling stays, the power dynamic can go); this dream enables Shigure to in fact go against the curse, not be controlled by it
• Akito is initially a friend, a little sister, only eventually a romantic interest when forced to confront it after Kureno happened
• Akito is raised as a god, she had no regard as to how her actions have impact on others; because of Akira early on instilling her god complex, contrast with Ren’s disdain toward her and her position, she grew up not knowing how to develop real human connections
• Along the way, a one-sided romantic relationship develops on Shigure’s side; he expresses his love for her early on; he comforts her when she is abused by her mother
• It is not explicit in the text whether they had an actual relationship; a lot of people subscribe to both schools of thought: Shigure and Akito romantically having a relationship before Kureno, or Akito and Kureno having a relationship first with Shigure just having one-sided feelings
• Akito relied on Shigure since Akira’s death; other zodiacs (including Yuki who was closest to her at that time) referenced Shigure to be closest to her; I have a feeling Akito never fully understood his love, as she referenced she always felt fear for him the most, he was the “most distant,” that he didn’t care to be alone; this is why Akito is “most afraid” of Shigure; she knows she does not have power over him
• However, Akito and Shigure clearly, despite feeling strongly toward each other (Akito in secret), have differing views of their relationship; Shigure wants her exclusively, but Akito attaches herself to others and expressed that she is not accountable even if it hurts him
• Akito and Kureno (who I assume in canon are already close as kids) grow more dependent of each other when his curse breaks; Akito ordered he is isolated and only interacts with her, clung to him as a way to uphold the zodiac curse; Kureno in turn let her, keeping Akito imprisoned to her web of lies; this does not go away over the years, leading Shigure to feel lonely and bored, so he begins to date Mayu after empathising with her re: her feelings toward Hatori
• Akito must have started sleeping with Kureno after the Hatori-Kana incident; having thought that she had to romantically connect with the zodiacs, she went and forged that bond with Kureno in the absence of the zodiac bond; if they started a sexual relationship earlier, Shigure should’ve found out earlier too? Unless they kept it under wraps so carefully…
• Upon learning of Kureno and Akito’s affair, Shigure’s human side is furious although I can imagine his zodiac side incredibly resistant to have negative feelings toward his god; this proved to him that Akito sees him just as cursed as the others, he is not an equal
• Unable to express his hurt and autonomy directly at Akito—they are not communicating—he sleeps with Ren, which proved to be a stupid, impulsive, vindictive, malicious decision
• Shigure is remorseful having impulsively and vindictively slept with Ren as it did not effectively land the message to Akito; this was a show of vulnerability he has not had before, and in light of how Akito responded to it, he carried his remorse in such a cold, indifferent, and flippant way
• Shigure gets over it quickly, wanting to forget about it (“that was a long time ago”), tired of it, but remains angry at Akito, and so they continue not directly communicating with each other beyond the banishment; remaining selfish and childish, he refuses to give in and be transparent so long as Akito keeps reinforcing her power over him
• Akito does not understand why Shigure would betray her like this; instead, she takes this as another threat to her bond, just like Kureno’s curse breaking
• When Akito ordered him to leave, he followed as he could not refuse the god; there is also a power dynamic in play relating to the hierarchical structure of the Sohmas
• Akito keeps bringing up this as she is not getting a resolution she is happy with (i.e., why did Shigure betray her, is their bond not in force?); she has a Ren complex, and so she fixates on Shigure’s betrayal as this makes her feel second best compared to Ren
• I believe they begin a sexual relationship after his banishment; they are passive aggressive with each other, at a Cold War, not quite communicating their feelings directly, but I can imagine a lot of sexual tension; in the main timeline, he frequently visited her despite his banishment, and she expected him to despite the betrayal—they almost always try to one-up each other, there’s always power play involved whenever they are together; they make each other feel bad; there’s always feigned indifference, jealousy, hierarchical differences in the family and the zodiac-god dynamic, gender, age, all these things at play
• The curse itself is not the problem, but the social constraints that come with it (Sohma estate hierarchy, parents’ treatment of their children because of it, the Cat House)
• Shigure does not feel constrained or impacted of the curse except for Akito’s dependency to it that prevents them to love each other
• He is extremely manipulative, cold, calculating, and selfish where Akito is concerned (i.e., sleeping with Ren, the box thing that led to Rin’s confinement in the Cat House)
• Shigure’s objective was to break the curse to free Akito of it; he plots this, and this develops to be Tohru’s objective eventually too; I believe he begins this during the Hatori-Kana incident, and after finding out Kureno and Akito are sleeping together, add to that the loneliness of his banishment; he has early self-awareness of how the curse is breaking everyone including a self-destructive Akito
• Shigure’s personality type however is that he is rather laidback, takes everything in stride; Shigure as a character is a passive schemer; he lets others “with more stakes” act, he watches as it unfolds; things only change for him when the curse breaks for everybody and he can finally openly love Akito
• He knows exactly how to push people's buttons, and at that moment he was definitely jabbing at Akito's insecurity about her repressed feminine side. What does Akito hate almost just as much as her mother? Femininity. Not because she actually hates it, but because she's cannot be a woman as long as she insists on remaining God. So Shigure, in saying that, makes the response hurt in multiple ways: That Akito looks like her mom, that he slept with her mom, that Shigure prefers a more feminine Akito and thus denying seeing her as a God.
• Meanwhile, Akito learns slowly over the course of the main timeline that her actions have consequences, have impacts to the bonds she has with the zodiacs, particularly the younger ones (Yuki, Haru, Momiji, Kisa)
• Shigure has good understanding of people; he is very perceptive, and he observes well; Shigure makes biting remarks at people to push them over the edge; a personality thing, but this helps other zodiacs to their own self-actualisation
• Shigure’s strategy to break the curse is to take opportunities to remove Akito’s hold on the zodiacs; picking & testing the bond
• Shigure described himself as “weak, intolerant, and worthless, the worst kind of man.” His refusal to be vulnerable, while he is in fact deeply hurt (i.e., his fixation whenever Kureno is mentioned/involved)
• After hearing from Kureno, Shigure gradually starts opening lines of communication with Akito (i.e., giving her a red paper flower, the post-restaurant confrontation)
• Shigure orchestrated Kureno and Tohru meeting so Kureno can feel guilty about his choice after speaking to Tohru
• During the post-restaurant confrontation scene, Shigure is looking coldly at what we presume is Akito when she is on another one of her "I'm God and I'm special" ego trips. He is looking at her like that because he feels deeply misunderstood. She fails to realize she isn't special, that she shouldn't cling to the idea of God for people to love her, because he has always been there loving her. That's why before her ego trip he reminds her of the scene with the camellia flower and how he has always thought about her the most. And he is not facing her directly, his face is intentionally hidden, depicting how hard it is for him to be telling her this now because he already told her that, shown her his feelings in many ways (at least obvious to him) and that she should understand that by now. You can also feel this with Yuichi Nakamura's layered voice acting. Not to mention that when he reminds her of the scene of their childhood he is using informal speech in opposition to his formal greeting and small talk with her when she first enters her bedroom. This shows that Shigure is being honest there and very vulnerable. At least this is far as he is willing to compromise himself at that point, both as a man and her lover. The ball was then in her court and as I have already stated, she failed to see Shigure's feelings for her without the betrayal (which I can perfectly understand at that point; she still hasn't healed and she was still the God at that point). She also felt she was being tested because Shigure can be a bit too cryptic at times. Lastly, the sex scene was NOT PLANNED AT ALL. Why would Shigure leave the window open them if that was his plan? And foremost, it was Akito who unconsciously provoked him to get vulnerable with her, which triggered their sexual tension and then she used her femininity to ultimately stop him in his tracks, a weapon she consciously/unconsciously picked up from Ren to use. And sadly she felt she was cornered and actually losing him so she desperately used it.
• Shigure must have been shocked when Akito turned up at his house after Tohru fell; this is the first instance they treat each other as equals
• ”I love the amount of time needed in the story to discover what Shigure’s goal is, and how much sense it gives the overall story retrospectively. And when you understand that he is. behind. almost. everything.The chess master who invites himself in the game Akito and Ren are playing and completely overtakes the board”
• He is always in control of himself, and is the only one who knows how to tame his own feelings and his attitude to coldly assess a situation and respond to it. His betrayal of Akito were both in rage and calculation, in full knowledge of causes and consequences, with plans and counter-plans for them. He is the kind of character who never explodes but will play the long game to enact his revenge; “Shigure is the only one of the main characters whose depths of bad match the heights of his good.”
• ”His goal, ultimately, proves to be good, but he is the only character ready to dirty his hands and deal with the unsavoury aspects of slowly unravelling a whole isolation, controlling, abuse-inducing system and pull his loved one out of this mess. He will do what needs to be done, meaning he will manipulate everyone, create conflicts and confrontations, force the other characters’ development, even if it hurts them, even if it hurts the one he loves, no matter the collaterals. (I would argue in his defence that undoing a centuries-old curse that is supposed to represent abusive and unhealthy relationships couldn’t be done without heartbreaks and tears).”
• Shigure in Fruits Basket ultimately “put his trust in fate while giving it a nudge”; “he is both Akito’s main antagonist and her love interest, and god, do I love Childhood sweethearts to Lovers to Enemies to Lovers trope”