I Am Writing a Diary in a Crossover Manga

"You can't see it?"

Sanzenin Nagi looked at the notebook in her hand and immediately understood.

"Ah, so it's that classic setting."

Since she wasn't the owner of the notebook, she couldn't see its contents.

"Well~ Maria isn't one of the chosen ones, so it's normal that she can't see it."

"Is this kid really starting again?"

Hearing Nagi's words, Maria almost instinctively felt that the young lady was having one of her episodes again.

She could always gauge the level of trouble she was about to face based on the severity of Nagi's enthusiasm.

Maria could only pray now, hoping that Nagi wouldn't be too troublesome this time.

She had long since given up resisting.

After all, this girl had a three-minute attention span. Once that time passed, she would surely return to her usual self—Maria was confident in that.

"Alright, so what has caught your interest this time?"

"A person—someone who seems very interesting to me."

Sanzenin Nagi didn't bother correcting Maria's attitude. It didn't matter. She just needed Maria to help her investigate this person.

Since Maria wasn't one of the chosen ones, no amount of explanation would matter if she couldn't see the diary herself.

"What's the name?"

"Amamiya Ren."

"Age?"

"Should be between 15 and 17 years old."

"Place of residence?"

"Not entirely sure, but I know it's in Beika City."

Maria suddenly felt that something was off.

Nagi knew his name, approximate age, and even his specific city.

Beika City—the famous crime-ridden city?

Although high crime rates were common in island nations, Beika City was on a whole different level.

And now, Nagi was directly naming Beika City. Clearly, this wasn't just a coincidence.

But Maria was also sure that Nagi hadn't left the mansion in recent days and had never interacted with someone named "Amamiya Ren."

"You're not just playing some new game, are you?"

Maria remained skeptical as she proceeded with the investigation.

The Sanzenin family had excellent intelligence networks, with information channels spanning the globe. They could obtain intelligence with money—and money was the one thing the Sanzenin family had in abundance.

Because of their vast resources, it didn't take long for them to compile a character file based on the clues: "Beika City," "Amamiya Ren," and "15 to 17 years old."

"His background is surprisingly simple."

The file was clear and concise.

[Introverted, withdrawn, not good at socializing, and lacks a strong network of connections.][Mediocre relationships with classmates, with no notable friendships.][No bad habits, no online presence.][Orphan, no records of his parents.][Works on weekends, financially struggling.]

"No bad habits, no online presence, poor social skills, no parents, struggling financially… He's practically a blank slate."

Then Maria checked the photo.

"Half his face is covered by glasses, his slightly wavy hair is a bit long, and he looks somewhat unkempt—clearly, he doesn't take much care of his appearance."

"That's probably why he struggles socially."

His looks weren't bad, but his lack of grooming made him appear more ordinary.

However, Maria personally found him somewhat handsome.

But that wasn't the issue that puzzled her.

"Why are you so interested in this person, Nagi?"

"You know his name, age, and general location—so he's clearly someone you're familiar with. But from his profile, he doesn't seem like someone you'd normally cross paths with."

Maria wasn't referring to social status but rather the complete lack of overlap between their lives.

Nagi often left messages online, yet this boy had no digital footprint.

So how had they met?

Maria was perplexed.

Meanwhile, in Beika City

Inside a large apartment that had become suspiciously cheap due to a past incident, Amamiya Ren was taking a bath.

After washing up, he sat down, opened his diary, and looked at it with reverence.

Suddenly, new black-inked text appeared on the page:

[Day 1 diary entry complete.][Achievement unlocked: First Entry.][Roulette prize pool activated.]

A massive, glowing roulette wheel appeared before Amamiya Ren.

It had a winning indicator and was divided into multiple sections, each labeled with a different name:

Naruto, Bleach, One Piece, Reborn!, Negima, A Certain Magical Index, Persona, Demon Slayer, The Strongest Disciple Kenichi, Marvel, Genshin Impact, Fate, High School DxD, Dao Gui Yi Xian, Lord of Mysteries…

Many of these were things Amamiya Ren could understand and accept. But there was one he absolutely didn't want.

That cursed Dao Gui Yi Xian.

Amamiya Ren immediately clasped his hands together and prayed with deep sincerity.

"Anything but Dao Gui Yi Xian, please!"

Before his reincarnation, he had heard of Dao Gui Yi Xian, but only in passing.

It was infamous. There were countless bizarre jokes about it—just like how, in reincarnation novels, you should never name yourself "Li Huowang," lest you end up doomed to suffer endlessly.

Although Amamiya Ren had never personally read Dao Gui Yi Xian, he knew its story and setting were overwhelmingly chaotic—perhaps even more confusing than the Cthulhu Mythos from Lord of Mysteries.

He didn't want to be dragged into that madness.

As an ordinary person, he simply couldn't handle it.

After finishing his prayer, he reached out and lightly touched the roulette wheel.

The moment he made contact, the wheel spun at an incredible speed.

Slowly, it began to decelerate…

And finally, it stopped on—

[Persona.]

[Characteristic acquired: Unruly.]

"Unruly? Is this referring to the protagonist's ability to wield multiple Persona masks?"

Amamiya Ren understood the concept, but he felt slightly disappointed.

"Seems like purifying my body didn't improve my luck after all."

He continued reading the description of [Unruly], hoping to gain a better understanding.

[Unruly]: The ability to accommodate multiple distinct personalities while maintaining the individuality of each personality.

"Ah, that makes sense. The protagonist of Persona needs to wield multiple Persona masks, so this ability is necessary."

"A Persona mask represents an aspect of one's personality—various emotions and states of consciousness. Normally, each person can only have one Persona. However, only a protagonist with the 'Unruly' characteristic can wield multiple Personas."

"But wait… Does this mean I won't develop multiple personality disorder?"

If his ability maintained the uniqueness of his core personality, then in a way, wouldn't that prevent mental illness?

But in a normal world, unless someone experienced extreme suppression, they wouldn't develop schizophrenia—at worst, they'd suffer from depression.

It was useful, sure, but… not exactly game-changing.