Chapter 1: I am Tom Riddle, Send Money
"I am Tom Marvolo Riddle, a powerful wizard. Due to an accident, my soul was sealed in this diary. If you are willing to help me break the seal, I will reward you greatly once I return to the wizarding world and reclaim my power."
It was past midnight when Kasumigaoka Utaha sprawled across her bed, her loose pajamas draped elegantly over her. Between her fingers rested a black diary that looked painfully ordinary—yet her gaze lingered on it with wary fascination.
The book had appeared on her desk just before lights out, as if delivered by an unseen hand. Utaha had tried to ignore it. Curiosity won. She flipped it open and discovered that no matter how far she turned, the pages never ended. A thin spine, and yet—endless paper.
Only one passage had been written, that audacious introduction from a supposed wizard. The letters were not in Japanese but in refined, archaic English, the kind one might expect on parchment. It felt absurd, and therefore—dangerously credible.
"Wizards… really?" she exhaled. "This is ridiculous."
She was not easily shaken. Since enrolling at Toyogasaki Academy, her grades never strayed far from the top, and rational thought was her refuge. But this diary mocked rationality at every turn.
Who was this "Tom"? What was this so-called wizarding world? Why had the diary found her?
Even as questions piled up, she did not write a single word. For all she knew, the first stroke of ink could be a contract.
Maybe she'd ditch it tomorrow—leave it on a park bench and let Tokyo's morning crowd decide its fate.
The idea died as quickly as it came. Earlier, she'd tossed the diary aside. It had reappeared in her hands the moment she thought about it.
Bound. To her.
Utaha patted her cheeks. Enough dithering. If there was a truth, she would prise it out.
She settled at her desk, fountain pen poised, searching for a first sentence: a courteous greeting? A veiled question?
Before the nib touched paper, fresh text bloomed across the page. This time, it wrote itself in her own language.
[Hehe, I was just joking earlier. You didn't really take that wizard nonsense seriously, did you? Surely no one is still staring at a notebook, agonizing for ages over how to reply? No way, no way.
Alright, joke's over. Let's get serious.
First, an explanation. This diary is my cheat—something I carried over when I transmigrated into this world. As long as I write in it daily, I'll receive rewards.
As for my name… my mother always said the world is dangerous. A boy should guard his privacy outside. So don't try to find me—I am the man you'll never obtain. If you insist on a label, "Mysterious Person" (or, if you like, "You‑Know‑Who") will do.
Anyone able to read this diary is—per the diary‑novel tropes from my previous world—probably the heroine of her own story.
To be honest, I don't know exactly who's reading right now. From my investigation, this world is a patchwork of anime, games, novels, and even films I once consumed. Calling you a "character" may feel insulting, but that's how my memories catalog you.
Or maybe those memories were planted by some bored, higher‑dimensional prankster. Who knows?
In any case, don't worry. You have wills of your own. The stories I remember are just rails. By the time this diary reaches you, the plot may already have jumped the track.
All I can do is record, as neutrally as possible, the versions I remember. Compare them to reality, or treat them as bedtime reading.
I'm curious how you—heroines across different stories—will bend the futures I recall after reading about yourselves and each other.
One reminder: you can't speak of this diary to outsiders. However, those who possess it can still communicate with one another. How you interact is your business. Personally, I think cross‑work heroine collisions sound delightful.
Now then, spoilers.
I wanted to start with Yukino Yukinoshita and Kasumigaoka Utaha, two heroines who were wildly popular in my previous world and showed up in almost every crossover. But according to my research, their stories won't truly ignite until next year. I haven't interacted with them yet, so I'll set them aside for now.
Instead, let's talk about someone urgent: Hoshino Ai, the idol.
I hope you read this, Ms. Hoshino. Opinions about you varied in my past world, but after watching your performances here, I sincerely hope you keep shining.
At fifteen, you may already have met Hikaru Kamiki. Whatever your status with him—listen carefully: stay far away.
Whether or not he's the true mastermind behind your eventual death, Hikaru Kamiki is a scumbag who preys on talented girls. If you're pregnant already, keep your location hidden. Otherwise a deranged fan named Ryousuke—likely nudged by a hidden mastermind—could endanger both you and your attending physician.
If it's come to that, hire a detective. Kogoro Mouri in Beika, Tokyo, and Shionji Yūko of the NEET Detective Agency are solid choices. If you visit Mouri, make sure the first‑year elementary school boy named Edogawa Conan is present—it will improve your odds.
That's enough for today. I've written over a thousand words and it's late. I have to play with my adorable sister in the morning. Let's see tonight's reward—hopefully nothing too disruptive.]
"You have read the diary for the first time, and you have gained 1 reading value."
A mechanical chime seemed to echo in Utaha's ears. Her expression grew even more complicated.
---
The room was quiet save for the soft hum of her computer. Utaha stared at the diary, then at the ceiling, then back again. The words she'd just read were outrageous, yet meticulously composed—like a confession performed on a tightrope.
A transmigrator. A diary that links different heroines across worlds. A patchwork Japan where stories overlap.
Kasumigaoka wasn't a common surname. The fact that she had received the diary made it statistically likely that she was the "Kasumigaoka senpai" mentioned within. She would be a third‑year in a year's time. "Senpai" would fit.
But a junior boy as the male lead? Or a junior girl, if the story veered into yuri?
Utaha pressed a palm to her forehead. It didn't matter. Not now.
The Mysterious Person claimed she was wildly popular in his previous world—dragged into every crossover like a convenient storm. The term "crossover" wasn't standard in Japan's ACG circles, but she understood the gist.
If given a choice, she would rather believe in actual wizards. A wizard might cast a clean erasure spell on an embarrassing past.
So that's why he hides, she realized, jaw tightening. "I am a man you cannot obtain"—what an infuriating line. If she knew his identity, she might march over tonight, kick down his door, and demand the full script of her future.
Had Yukino Yukinoshita read the diary too? If so, Yukino was likely grinding her teeth as well.
Speculation wouldn't help. Verification would.
She exhaled, steadied her heartbeat, and focused on the name that mattered most right now: Hoshino Ai.
The diary's account had been surprisingly even‑handed. A fifteen‑year‑old idol, possibly pregnant out of wedlock—that alone could end a career. If Utaha had seen a similar scandal on television, she might have muttered something scathing about the industry's filth.
Even in anime, a girl like Hoshino Ai was a lightning rod for controversy.
Schadenfreude flickered—then died when Utaha imagined herself dissected by strangers' gossip. No, if the diary was real, then Ai needed help, not judgment.
Utaha powered on her PC. A few searches later, she'd found the idol's basics and even slipped into a fan club to read the chatter.
Orphanage upbringing. Debut at twelve. Center of the modest idol group B‑Komachi. Those eyes—sparkling, unforgettable on first glance.
"But her figure isn't as good as mine," Utaha decided dryly at a glance, then scrolled on.
Three years into her career and still under a hundred thousand followers on social media. Definitely third‑tier. Yet the comments buzzed with fresh accounts, excitement spiking in the last couple of months.
Photo by photo, Utaha noticed the shift. In the early years, Ai's radiance felt like a costume she didn't own—makeup sitting atop uncertainty, poses learned but not lived. Money was tight; practice was endless. That made sense.
Recently, though—her styling clicked. Her stage presence deepened. The smile reached her eyes. She'd discovered how to wield charm like a spotlight.
A beautiful girl who learns how to project allure will always draw new fans.
Utaha's thoughts circled back, inevitably, to Hikaru Kamiki. The diary called him a beast who fed on gifted girls and hinted he was tied to Ai's future tragedy.
"Orphanage to idol to seduction to scandal to a mad fan… what a rotten outline," Utaha murmured.
Would Ai also be reading this diary? If she was already in love, would a sudden supernatural warning change anything?
Utaha wasn't about to crash a stranger's life based on a single night's discovery. The Mysterious Person himself had only warned in suggestion, even recommending detectives by name. If Ai saw the warning and wasn't blinded by passion, perhaps she could swerve away from that grim future.
Besides, the other holders—what were their intentions? Better not to be the first fish to break the surface.
She closed the fan club tab, the glow of the monitor cooling the room to steel. "I'll wait and watch," she decided. "Let's see what the Mysterious Person writes next."
Across Tokyo—and beyond—other girls stared at the same moonlit pages, wrestling with the same decision. Some, impulsive or compassionate, were already booking tickets to B‑Komachi's next live.
Either way, it would be a restless night for many heroines in Japan's tangled web of stories