Toyosaki High School, located in the bustling city center, was the perfect place for both business opportunities and idle gossip. To the west lay Mihana Town, to the east Akihabara, and a little further north, a bustling Chinatown. A half-hour walk south brought you to the Tokyo Dome, overflowing with concerts and entertainment. Even Dr. Agasa, with his collection of eccentric inventions, was close enough to visit in Mihana Town.
For Renji Miyauchi, it was the ideal stage. He had already planned out his high school years in detail long before the diary entered his life. In his free time, he intended to search for familiar faces from his past life's anime worlds, investigate whether true monsters and ghosts roamed here, and collect keepsake photos with characters he once admired from a distance. He wanted to see Kessoku Band's first live performance, listen to MyGO!!!!! play Haruhikage, and watch from the sidelines as the protagonists of stock-market-themed works chose their fates.
Of course, he also admitted another reason for choosing Toyosaki High—Kasumigaoka Utaha's elegant stockings. "Who doesn't like stockings?" he had chuckled to himself. Yet now, his cheat had arrived far later than expected, gifting him a Pure Yang Body—a troublesome power that made him easily excitable.
"If I hadn't managed to barely control this physique, I wouldn't even consider attending school," Renji muttered, feeling the constant heat simmering in his blood. "I've been building my career for years, and the money I've earned is more than enough for a normal life. I could've focused on personal matters… but now, everything has to be re-planned."
He had started early not only to provide for his sisters but also to build confidence—so that unlike his past life, this one wouldn't be wasted in mediocrity. As for the cringey videos that built his reputation, well, Renji never appeared in them himself. He only wrote the scripts and let others act. Miyauchi Kazuho always teased that he'd never find a girlfriend with such eccentric projects. Renji knew better.
Now, though, his perspective had shifted. Instead of chasing girls, it amused him more to see how his diary entries might shake heroines' hearts.
"I mentioned Yukino Yukinoshita and Kasumigaoka Utaha before. According to the logic of diary-style novels, people mentioned will almost certainly receive a diary copy." He smirked faintly. "I wonder what Hoshino Ai thinks now, seeing glimpses of her future."
As for Yukino and Utaha, Renji imagined them agonizing all night over his words. Especially Yukino—so obsessed with perfection. If she realized her struggles and ideals were just story beats in someone's novel, it might break her. But then again, Yukino was strong. At fifteen, people are impressionable, but they are also resilient. If she were weak enough to crumble from this, she would never have become so beloved.
Renji leaned back, musing. "I've read enough web novels to know how to play the role. I can act like one of those behind-the-scenes masterminds in chat group stories, tricking and guiding the heroines while staying untouchable."
With that decision, he picked up his pen and began his second entry.
---
Meanwhile, in another corner of Tokyo, the Shinomiya estate stood in cold, imposing silence. Within her bedroom, Kaguya Shinomiya sat upright, awaiting her maid Ai Hayasaka's report. Last night, when she had laid down to sleep, a black diary had fallen squarely onto her face from nowhere. The windows were sealed, the doors locked. It had simply appeared.
Her first instinct had been to punish the prankster. But when she opened the diary and saw the strange English words—"I, Tom, send money"—and discovered that it was indestructible and endless, her instincts told her it was dangerous, but also valuable.
Following her training as a Shinomiya, she had quickly written: "I am Kaguya Shinomiya. What is your purpose?" But instead of an answer, a prompt echoed in her mind: [Your accumulated reading value is insufficient. You cannot unlock the diary's usage permission.]
That one line had shaken her more than any lecture from her strict family. Her lips pressed tight, she had written another question. This time, the diary explained: each day she read it, she would earn one point of "reading value." After seven days, she would unlock permissions. Until then, she could only read, not interact.
"Who is Tom? Does magic exist in this world?" she tried again. The response was the same: no permission. Her carefully penned words faded from the pages.
For over half an hour, she tested it from every angle, only to learn a handful of rules: the diary would update daily; reading it granted points; only holders could see it, and mentioning it aloud twisted into meaningless actions before others' eyes. When she tried to speak of it to Hayasaka, her words distorted, and Hayasaka merely poured her tea as if nothing strange had been said.
Still, Kaguya persisted. Finally, a new thousand-word entry refreshed before her eyes, shaking her worldview. The text spoke of Yukino Yukinoshita, Kasumigaoka Utaha, Hoshino Ai, Hikaru Kamiki, and even the legendary Tom Marvolo Riddle. Her heart, long taught to submit to duty, began to beat with curiosity again.
By morning, she had Hayasaka investigating every name mentioned. The Shinomiya family's network quickly produced files: Utaha, Yukino, Ai, Conan Edogawa, Kogoro Mouri, Yūko Shionji. Some details were missing, but the evidence was strong enough. When Hayasaka presented her findings, Kaguya compared the profiles. Utaha's beauty stood out instantly. Yukino's flawless academics impressed. Ai's scandalous life shocked. And Kamiki's depravity disgusted.
Touching her cheek, Kaguya whispered, "So, these are my rivals… and perhaps, my opportunities."
Just then, the diary refreshed again with Renji's latest words.
---
[I didn't sleep well last night. I checked the news today—turns out the daughter of the Suzuki family was nearly killed at a university reunion. Conan's story should be around the 'Bandaged Man' case right now.
This world follows strange rules. APTX4869 can shrink a grown man into a child within minutes. And yet, strong liquor can temporarily reverse it. Where does the missing body mass go? Into the void? Into energy? Nonsense.
Still, Detective Conan's story, despite its black technology, runs on logic. But Kaito Kid's tale goes further—there's Akako Koizumi, a real witch, and the Pandora Gem, said to hold eternal life.
When I left my past world, neither series was finished. I don't know who the true villains are. Frankly, I don't care to get involved. Better let Conan and Kid carry their burdens. They're geniuses. If you step into their world, you'll be dead in minutes.
Remember this: the Black Organization are not people you can trifle with. They're world-class terrorists. Stay away from Mihana Town—it will have the highest murder rate in Japan for years to come.
As for Ai Hoshino—her story hides the supernatural too. If she's pregnant now, her children are reincarnated souls. They'll one day investigate her death.
Exciting? Maybe. But don't forget: even great authors falter. Predictions are fragile. Her fate isn't set in stone.
I'll say this once more—don't chase justice. Live quietly. Survive. Even if the sky falls, there are other protagonists to hold it up.]
---
Kaguya closed the diary, eyes thoughtful. Today's entry was shorter, but the impact was no less earth-shaking. She reached for Conan's file again, her fingers trembling ever so slightly.