Something something… the idea that Nanami is actually a cow… something something
This idea works so well with my interpretation of Utena as an allegory for overthrowing systems of oppression (specifically the patriarchy). To me Nanami represents the dehumanization of women (oppressed minority) under the patriarchy and how building your identity around a man (oppressor) is the only way to be seen as almost human. Nanami is a cow, but by sentencing her entire identity around Toga and being his sister she can become human, she is so scared of being seen as an animal (as seen is the eggpisode). I think this is why she becomes almost a background character after thinking that Toga is adopted, only appears as a small cameo in the manga and is a cow in the movie. She built her entire identity on being Togas sister, someone who is irreplaceable to him, and now that she thinks she isn’t it falls apart.
Also I don’t think Nanami is romantically in love with Toga, I think it’s like with the kitten, she’s jealous. And I think she thinks that if she can somehow fulfill Togas romantic needs that she won’t have any competition for his attention.
thinking about rgu's assertion that it's a complete misunderstanding to think that touga doesn't care about nanami and saionji. he does care about them. he cares about them so much that he, someone who does not believe in sincerity or trust, is willing to emotionally beat down, manipulate, and abuse them to keep them close to him, to keep them on a short leash and that leash in his hand. because he absolutely cannot bear the thought that they can live without him.