At the same time—AIM Analysis Laboratory, in Kiyama Harumi's office.
"So even that girl we met last time has fallen victim, huh..." Kiyama Harumi muttered quietly, her expression unreadable. She let out a faint sigh and looked at the self-blaming Uiharu Kazari, gently trying to comfort her. "Perhaps you could request permission to use the Tree Diagram to find a way to break [Level Upper]."
"Eh?! If we can use that supercomputer, then we'll definitely find a solution!" Uiharu exclaimed, hope lighting up her face as her earlier despair was swept away. "I'll contact Selene-senpai and the others right now!"
The Tree Diagram was Academy City's pride—the world's most powerful supercomputer. It was said to be so advanced that no one could surpass it for at least twenty-five years. As long as it was given accurate data, it could perform perfectly precise predictions of future outcomes.
Theoretically, by calculating the motion of every air molecule on Earth, it could even predict the weather with absolute accuracy. That was why Academy City's forecasts weren't forecasts at all—they were prophecies, declarations of certainty rather than possibility.
To the general public, the Tree Diagram was constantly used for meteorological analysis. Because of its immense value, it was a frequent target of outside organizations, so—under the pretense of security—the Board of Directors launched it aboard the artificial satellite Orihime 1, orbiting high above Academy City.
But was that really its true purpose? Uiharu didn't know, but Selene certainly did—she was one of the few granted access to it. The Tree Diagram's real function wasn't weather prediction; it was to simulate and forecast experimental outcomes. Experiments like the Railgun Mass Production Plan and the Level 6 Shift Project all relied on it.
As she watched the suddenly excited Uiharu, Kiyama couldn't help but think of her own students. Her chest tightened with sorrow. "If only the request gets approved..." she murmured softly.
"Eh? What was that, Kiyama-sensei?"
"Nothing... don't blame yourself too much. Go rest for a while. I'll make some coffee," Kiyama said gently, standing up slowly. For some reason, her voice seemed distant—almost lost.
"But... now's not the time to rest! Saten's still—" Uiharu protested anxiously. Even with Selene's reassurance, she couldn't help but worry. She believed—she had to believe—that Saten Ruiko would wake up. But she also wanted to help, to do something useful, anything but sit and wait.
"That's exactly why you should rest," Kiyama said, placing a reassuring hand on her shoulder. "If your friend wakes up but you collapse from exhaustion, wouldn't that defeat the purpose? Besides, submitting the request and receiving results will take time."
"Don't worry," she added softly, her voice carrying a rare firmness. "Everything will end well." Whether she was convincing Uiharu or herself, even she couldn't tell. With that, she turned and left the room.
"..." As the door clicked shut, Uiharu sat in silence. Thoughts of her best friend, Saten Ruiko, filled her mind. I'm so useless... I can't do anything... Her eyes burned, and before she realized it, tears were streaming down her cheeks again.
She wiped them away quickly. Now wasn't the time to cry. She had to stay strong. Just as she resolved to get up and look for Kiyama—
"Hmm?"
Her sharp eyes caught a glimpse of something white sticking out from the cabinet nearby. "This is... synesthesia?" The word on the document's corner immediately caught her attention.
Something in her gut told her—this was important.
Pulling out the papers, Uiharu spread them open. Inside were numerous research notes and academic papers—all about synesthesia. A chill ran down her spine as cold sweat formed on her forehead. "These are... all related to synesthesia..."
In that moment, she understood. Kiyama had lied. She wasn't just an observer in the [Level Upper] incident—she was involved. Maybe even... the mastermind behind it all.
And all this time, Uiharu had been reporting every clue she found... directly to her.
Regret and realization flashed across her face. "Why... why didn't I notice sooner? No—I have to tell the others right away!"
But before she could send the message—
"That won't do... you can't just rummage through someone else's research notes like that."
As the door creaked open, Uiharu Kazari froze in place. Seeing Kiyama Harumi standing there, she knew there was no escaping this. Her voice trembled as she asked, "Why?"
"So it's come to this, huh..." Kiyama let out a quiet sigh. "Because I, too, have my reasons—reasons that leave me no choice."
"Lies! What kind of reason could justify endangering the lives of tens of thousands of people?!" Uiharu shouted, tears welling in her eyes. Her voice broke, weakening as guilt and despair overcame her. "I was so stupid... it's all my fault! I trusted you, and now... Saten's situation is because of me!"
"I'm sorry..." Kiyama said softly, a pained expression flickering across her face. Looking at the self-blaming girl before her, she sighed deeply. No matter what she said now, it would change nothing. The truth was that she had used Uiharu.
"I promise... everything will end well." Kiyama's tone carried a strange mix of sorrow and determination. She stepped closer, emotions—pain, memory, confusion—flickering across her eyes. Then, with a gentle but firm motion, she struck Uiharu at the back of the neck. "Forgive me... just rest for a while."
As the unconscious girl slumped to the floor, Kiyama's expression twisted with inner turmoil. In Uiharu's face, she saw her students again—their bright smiles frozen forever in memory.
If I could, I wouldn't choose this path either... but I have no other choice.
Twenty-three applications to use the Tree Diagram—twenty-three rejections and endless bureaucratic stalling. Not one approval.
I can't wait any longer. I won't live the rest of my life with regret.
For those children... even if I can only let them see the sunlight one more time, I'll do it. Even if it means falling into hell, I'll go willingly. I have no regrets.
So forgive me...
Her eyes hardened again as resolve replaced hesitation. Time was running short—Judgment and Anti-Skill would soon be on their way. She had to move fast.
Quickly, she carried Uiharu to her car and placed her gently in the passenger seat. Looking at the sleeping girl with the flower clip in her hair, Kiyama felt her chest tighten.
Taking out the final, remaining copy of the [Level Upper] treatment program, she held it tightly in her hand. The brief look of sorrow on her face faded, replaced by steel determination.
Whether for my students... or for this girl's unshakable friendship... once my objective is achieved, it will all be over. No one else will have to suffer.
Taking a deep breath, she started the engine. The blue Lamborghini revved to life and rolled out of the parking space, speeding toward the bright exit of the underground garage.
"Children... wait for me," she whispered under her breath. "Your teacher..."
"...will save you. I swear it."
"This time, I'll do it my way. And I will keep my promise."