Shiori and Touga as ghosts and the absence of Nanami in Adolescence of Utena
Some questions I had when I first watched AoU were:
"What's up with Shiori and Touga?" "Why is Nanami absent?" and also "What the hell is That*?"
(*This thing. Alt text: small red crocodile like creature with a string coming from its belly)
In another post, I established that Touga is a ghost, and he's specifically been brought to Anthy's world by Utena who is mistakenly using him as the face of the trauma she's experienced failing to be a Prince and losing Anthy. There are lot of nods to this: the textual fact that he's a ghost, how he's dressed in black, and how he and Shiori exist in this strange space outside of Anthy's influence having conversations with Akio, another dead person. Through this line, we can pretty easily deduce that Shiori is a ghost as well: Juri's ghost.
Textually, in the movie, Shiori is strongly implied to be the girl Touga drowned saving.
This is an important callback to a story from the original series. In Revolutionary Girl Utena, Juri discusses how a boy drowned saving her sister but Juri forgot his name. Soon after Utena disappears from the world, everyone but Anthy forgets her as well even though the mark of how Utena has changed each of them remains.
Like Touga, Shiori is a ghost who has changed our protagonists but has not been called into the world.
This brings us to the questions: Why are Touga and Shiori dead? Why couldn't Anthy bring them into the perfect world she made for Utena?
Two possibilities: like Utena, they escaped or, we can take the movie at face value, they are dead.
I believe that Nanami escaped and that's why even her ghost isn't in the narrative. Anthy goes so far as to get one last silly jab in, but, Nanami is allowed to be free. Based off of that wild assumption I am making, I also believe Touga and Shiori did not escape and instead died.
There are a few clues. Touga spends much of the movie speaking through the phone to Akio who we also know is dead. Meanwhile, at the very end of the movie, Shiori herself surprises everyone by becoming a car to stop Anthy from leaving her traumatic world behind. Finally, Shiori draws that weird little creature with the string coming from its belly on Touga's shoulder.
"If it cannot break its egg's shell, a chick will die without being born."
The string coming from the belly of the creature is an umbilical cord. It replaces Chu Chu who represented Anthy's true intention. Chu Chu is no longer necessary because we know Anthy's true intention: to live happily with Utena. However, tbis new creature represents a new unknown: the consequence of Anthy's desires. Looming over Utena and Anthy throughout the film is the threat of choosing not to break out into the real world and grow up and, as a result, dying before you're even born.
Utena struggles with suicidal thoughts and Touga manifests these in her. Her pursuit of him throughout the movie can be read as her pursuit of death in the scene where he invites her to join him as he drowns in the elevator.
Meanwhile, Anthy struggles with returning to the security of her trauma. Shiori is her foil in that Shiori has embraced it and, like Anthy once did in the series, is trapping others in this world due to her own pain.
This also explains what happened to Touga and Shiori. They have both embraced the system put into place by Akio and, as a result, have died without achieving revolution long before the events occurred in this movie. When she becomes a car, Shiori in particular demonstrates that she is capable of leaving behind this world, but instead chooses to drag others down with her, something very in line with how she was depicted in the series.
Touga and Shiori died before they could break the world's shell, but Wakaba, Juri, Miki, and Saionji are on their way out after Utena and Anthy.