Censored Equation (検閲方程式 Kenetsu Hōteishiki) is a short story that is part of an anthology of short stories based on the Thus Spoke Kishibe Rohan series. It was written by Yusuke Iba (維羽 裕介 Iba Yūsuke) and published by Shueisha. Censored Equation was included with the September 2017 issue of Ultra Jump to coincide with the eighth episode release of the Thus Spoke Kishibe Rohan series.
It was then compiled in a collection named Rohan Kishibe Does Not Shout with four other stories, which released for sale on June 19, 2018. Censored Equation is on pages 157-198 in the volume.
Rohan was asked by Shueisha to write a short story on the theme of encountering the unknown, and so he visits a university library near Morioh to find out about aliens. Yuto Chikamori (近森 優斗 Chikamori Yūto), a graduate student, assists Rohan in finding documents because he was Rohan's fan. Rohan becomes interested in Chikamori when he finds out he goes to university studying mathematics and solving equations. One such equation is Drake's Equation, which is used to calculate the likelihood of intelligent life existing in our galaxy.
After perusing many of the documents and papers Chikamori provided to him, Rohan was satisfied with his research and began to pack his things. As he's putting away his reading material, he notices a notebook that Chikamori left behind on the desk. His curiosity piqued; Rohan reads through the notebook only to discover a massively complex equation written throughout it. The first page of the notebook is ripped clean in half, and the rest of the pages are the same equation seemingly copied and pasted over and over again. As he is looking over it, Rohan feels as though he is being watched from some invisible entity. Chikamori returns to the room to fetch his book and begins speaking in several different languages giving Rohan a warning not to pursue this any further. Rohan is confused by Chikamori's sudden change of attitude, but the student returns to normal as if nothing happened. Rohan asks about the contents of the notebook, and Chikamori indulges.
He reveals that the equation in the notebook is meant to tell of a way to cross dimensions, and the notebook belonged to his girlfriend. She had been attempting to solve this mysterious equation for two years before she suddenly fell into a coma. She has been asleep for three years now, and Chikamori has devoted his life to finding the solution to the equation, to satisfy his girlfriend's last wishes. Chikamori tells Rohan that the reason he could not solve the equation was quite simple... It was incomplete.
Rohan's interest in this story wanes as he tries to figure out how he could potentially use this information for his next short story. He uses Heaven's Door on Chikamori to find out the hospital his girlfriend was staying at and takes off. Before he leaves, he writes a note inside of the student that says he cannot visit the hospital, so the two of them do not awkwardly meet while he is visiting.
Rohan arrives at the hospital and enters the room where Chikamori's girlfriend is asleep in. It is a private room, which implies to Rohan that she comes from a wealthy family. He pulls over a stool and uses his Stand to read the girl's thoughts. Her face peels away into a book, with her pages being thin and weak.
He reads the contents of her early life before finally stumbling on mention of some sort of equation. Her memories are articulated in a strange way in that they were very easy to read and interpret for Rohan. He reads on.
Chikamori's girlfriend had discovered a book belonging to a physicist that told of an equation that could lead to accessing another dimension. She became engrossed in his findings and devoted the next two years of her life to trying to solve said equation. It was long and complicated, and she realized that it would take hundreds of years for someone to actually solve it from the beginning, so she figured that someone had to have attempted it in the past...
As Rohan reads the girl's memories, he continuously feels a persistent glare on his back. Nobody else was in the room with him, but the longer he read, the more he felt like he was being watched. He read on.
The girl discovered that there were clues to the equation hidden throughout society that can be traced back hundreds of years. Hidden in oil paintings, news reports, and ancient texts. She compiled her findings one day at the library and finally came to a conclusion, one that she had been looking for two whole years. She braced herself in anticipation for something to happen as she solved it, but nothing happened. She wondered if she had really wasted two years of her life for nothing. She gave up and decided she would attempt the same thing tomorrow. As she was packing her things, she began to notice that all the written words she could see were replaced with numbers. The text on her coffee cup, the "shutting down" message displayed on her computer, and her name on the sign-out sheet were all written in numerals. Before she could even assess the situation, all the numbers turned to a 5, then to 4. She understood what was happening. It was a countdown. What it was counting down to, she didn't want to find out. She tried to destroy any evidence of the equation she could. She ripped out the first page and crumbled it up as the countdown reached 2. She frantically looked throughout the library for some way to dispose of this formula—the shredder, burning it, or pouring water on it were of no use. The countdown hit 1. She realized the only way to properly dispose of it was to put it somewhere nobody would look, and she crumbled it up and ate it. As the countdown hit 0, she felt a presence behind her.
The memories end there. Up until that point the feeling of being watched had grown increasingly on Rohan, but it had suddenly gone away. Rohan concluded that while it was unclear if the equation transferred someone's consciousness to another dimension, or simply overheated her brain, he figured it must have some mysterious power.
As he ponders these questions, he too begins to notice the words around him being turned into numbers. Realizing what was going on, he struck his arm with his Stand, and readied himself for attack. The numbers suddenly all became 5, and the countdown began. As the numbers trickled down, Rohan perceived himself to be merging between locations rapidly. As he was flung from Morioh, to Jimbo Town, and Kunini Press, he decided that there had to be some enemy for him to attack. He remembered that in the girl's last moments she felt the presence of someone (or something) behind her. As the countdown struck 0, Rohan activated Heaven's Door as something materialized in front of him. It was humanoid and had pale skin and pitch-black eyes. He attempted an attack, but it was no use, and he lost consciousness.
Rohan suddenly awoke to staring at the floor under the hospital bed. He read his watch. Two minutes had passed since he had passed out. On his arm, written with Heaven's Door, wrote "You will forget the equation after 10 minutes." He had enacted a fail-safe in case reading the equation in her memories triggered the same phenomenon Chikamori's girlfriend experienced.
The curse of the equation was activated upon learning its solution. Rohan notes that it shouldn't really be called a "curse," as it's more of a natural phenomenon of life, like gravity. He leaves the hospital room, and on his way out writes on the girl's face that she too will forget the equation, and as he leaves, she stirs in her bed finally waking up. Rohan approaches the elevators and meets Chikamori, who doesn't remember him as Heaven's Door erased his memory of that morning, and Rohan writes in him that he will also forget about the equation. Rohan hears his gasps as he enters his girlfriend's room, as the elevator doors close.
Rohan takes a train back to Morioh and daydreams about the events that just unfolded. He decides that the feeling of being watched was probably a warning mechanism. The same way that prey in the wild use that feeling to escape predators. He also realizes that in a few hundred years, when we have reached the technological singularity, when AI surpass human capabilities, the equation may finally be able to be solved. It is clear that is not meant to be solved now, not by any human.
He watches the sun set on his way home and has feelings of nostalgia looking at the lights of the city that pass. As he steps off the train platform in Morioh, the summer breeze feels good on his clammy skin.