Warning: The following contains spoilers for Wonder Egg Priority, Episode 9, “A Story No One Knows,” now streaming on Funimation.
As a 14-year-old girl who runs a big corporation, doesn’t have parents and was almost killed by her sister, Neiru has always been the most mysterious of Wonder Egg Priority's heroines. Episode 9 fleshes her out further, giving us more clues about her background and why she has a closer connection to the Accas than even she knows.
Neiru invites all the girls to her home for a party, who are surprised but very excited. There, Neiru finally explains that she was a "test-tube baby" artificially modified by a Japan Plati member -- in other words, she is the product of an experiment. Plati is an organization of geniuses to which Neiru also belongs, explaining why she has no parents but is able to run a corporation.
But Neiru is not alone, she had a friend with the same background named Kotobuki, who was a psychiatrist in charge of the medical department. Kotobuki was interested in the mysteries of life and experimented with near-death experiences. But eventually, her experiments went wrong and she entered a comatose state.
Neiru sees Kotobuki again as an egg girl in her dream, confirming to her that Kotobuki is really dead. But Kotobuki is optimistic and easygoing about it. Her death wasn't intentional, but she doesn't seem to regret it. Kotobuki says that she was captured by the temptation of death and it’s an “innocent sorrow” that smells sweet, but the Wonder Killer intterrupts before she can say more.
Kotobuki also tells Neiru that parallel worlds exist, including worlds where they are both alive. These parallel worlds might be the key to solving how dreams work. In Episode 1, when Ai asked the Accas if Koito can really come back to life, they didn’t answer, suggesting that they can’t directly revive someone. In this episode, though, Kotobuki also says that people only live once. If the girls can only see the people they lost in a parallel world, it would explain the Accas’ cryptic non-response. But this raises many more questions: are the dreams portals to the parallel world, or do the girls have to die in order to travel there?
Neiru and Kotobuki defeat her monster -- a doctor who wants to experiment on Kotobuki’s body -- by easily solving a problem that he couldn't, leading the creature to kill itself. Before Kotobuki disappears, she makes Neiru promise to end her life support so that adults can’t touch her body, being experimented on by others is her trauma. Neiru tries to keep her promise and invites all the girls as witnesses, wanting support from her friends as she ends Kotobuki’s life.
Rika and Momoe both disagree with Neiru’s decision. She did not tell them the whole truth about Kotobuki’s wish, leading to a misunderstanding over how Neiru can be so calm about taking a life. The pair storm off, but Ai senses Neiru is not as calm as she looks and goes back to find out the truth. Neiru cannot bring herself to push the button that'll end her friend's life, shaking at the thought of it. Ai helps to relieve the burden of guilt by offering that they push the button together, allowing Neiru to say good-bye to Kotobuki.
Rika and Momoe go to the egg place after they leave Neiru and accidentally see the Accas having a teleconference with Neiru’s secretary. Their conversations reveal that Kotobuki gave Neiru a hint about the temptation of death -- “innocent sorrow” -- but the secretary somehow deflected Kotobuki, suggesting that she can control the dreams to some extent. The Accas also confess that they are the root cause of the other girls’ suicides.
Add to this the idea of the parallel world and Neiru’s background with experiments and it’s possible that the Accas and Neiru’s secretary are experimenting on the girls in order to research a parallel world that only young girls with traumas can enter.
