With the release of the Five Centimeters per Second tankōbon, a work that had finished serialization two weeks earlier and whose hype had begun to cool, suddenly exploded in popularity again.
Until now, discussion had been mostly limited to readers of Sakura Weekly, its fanbase, its ecosystem, its little circle.
But tankōbon were different.
Tankōbon were for everyone.
Even though distribution wasn't nationwide in the strictest sense, regional coverage varied, with some prefectures and smaller towns lacking stock, the moment the book hit shelves across Japan, countless new readers got their hands on it.
Some came out of curiosity. Some came because friends recommended it.
Some came because industry critics praised it. Some bought it because several mid-tier manga artists had casually mentioned it on social media.
And once they binge-read the entire story in an hour or two…
They broke.
Unlike weekly readers, who had weeks to digest their emotions, tankōbon readers were hit all at once.
Their shock, disbelief, and heartbreak were far more intense than anything seen during serialization.
And so, just like before, but louder and messier, waves of newly wounded readers surged onto Sakura Weekly's official forum and poured into manga artist Shirogane's verified accounts across social platforms.
Within hours, the comment sections were in flames again.
"Author, are you human?! How could you end it like that?!"
"High school girl manga artist? Don't think being young makes you immune to criticism, I'm a middle schooler and I'll still roast you!"
"Just bought a stack of manga for my summer break. Thirteen volumes. Unfortunately, the first one I read was Five Centimeters per Second. Now I'm so upset I can't even eat. Damn you, Shirogane!"
"Takaki and Akari, that's really the last time they ever see each other? That's it?!"
"My stomach hurts. Literally."
"Hahaha… you're all exactly like I was two weeks ago. And I can't deny it, I'm enjoying watching newcomers suffer."
"Seeing others fall into the same emotional crater, is strangely satisfying."
Originally, the interaction between new and old readers was supposed to build long-term buzz and slowly boost sales.
But fate delivered a bonus event.
Because on the night of July 27th, something happened that no one expected.
A single comment appeared on social media from a name every manga reader in Japan knew:
Hoshizaki Aira.
A superstar manga artist. A regular in Monogatari Comic, one of Japan's "Big Six" magazines, a prodigy who debuted at seventeen.
Creator of two serialized hits with combined worldwide tankōbon sales near one hundred million.
Only twenty-one years old.
Extremely popular, frequently appearing on TV, variety shows, and talk programs.
Her influence wasn't small, it was titanic.
And she posted only one brief line:
"I recently read a debut work called Five Centimeters per Second.
It's really good."
Just a simple endorsement.
Yet in the Japanese manga world, it was the equivalent of a meteor impact.
Readers knew exactly what that sentence meant.
Aira never praised anything lightly. When she did, it always spread through the entire industry.
It instantly pushed Five Centimeters per Second into the spotlight far outside Sakura Weekly's ecosystem.
Because the moment a star at her level said "this manga is good," nearly the entire manga-reading population took notice.
It was similar to how, in Rei's previous life, Eiichiro Oda openly praised Your Lie in April, or how Yoshihiro Togashi publicly supported Demon Slayer when it was still at risk of cancellation.
It was only after a certain superstar publicly praised it that its tankōbon finally broke the one-million mark.
And two years later, once the anime aired, the series erupted like wildfire.
In a country with only a hundred million people, it achieved an unheard-of 80 million copies sold in a single year.
A number that crushed even the height of One Piece's Marineford boom, which had once hit 30 million.
Normally, the yearly champion only moved ten-odd million copies.
But Demon Slayer was not normal.
Its growth was absurd, explosive, an IP that went from nearly canceled to standing alongside Bleach, Naruto, and One Piece, eventually valued above ten billion USD worldwide.
Because of that history, the manga industry naturally paid close attention when a popular creator publicly endorsed something.
Which was why Aira's sudden, open praise for a work serialized in an entirely different magazine raised eyebrows everywhere.
Even veteran editors whispered to each other:
"Why would Aira boost a rookie from another company?"
Even Miyu herself was very surprised.
If Aira were a contracted artist of Hoshimori Group, this could've been written off as a strategic push arranged by the higher-ups.
But after asking her sister:
Misaki merely frowned, shook her head, and said:
"We have no connection to her. And she's serialized in a rival company's flagship magazine. We couldn't make her do something like this even if we tried."
That only made Miyu's expression twist into something odd.
"So she just read Five Centimeters per Second, cried her heart out, and decided more innocent readers should feel that pain too?"
"Watch your phrasing," Misaki sighed, though a small smile tugged at her lips.
Her clear eyes softened.
"But yes, Aira is a very straightforward person. She says what she thinks. If she likes something, she recommends it. I'm not surprised she'd post something like that."
Then her tone shifted, becoming more businesslike.
"And this is excellent news. Even if just a fraction of Aira's massive fanbase takes interest, it will push tankōbon sales up significantly."
That night, Rei naturally saw the post as well.
Aira's simple, elegant endorsement had already generated thousands of comments from her fans saying they would buy the volume tomorrow.
Rei stared at the screen, feeling dazed.
"Did the higher-ups arrange some hidden PR deal for me?"
He honestly couldn't think of any other explanation.
But after failing to make sense of it, he simply shrugged.
Whatever the reason, it wasn't a bad thing.
Meanwhile, in a luxury apartment across the city, Aira glanced at her phone, watching the thousands of replies pour into her post.
Her followers were buzzing, many promising to buy Five Centimeters per Second first thing in the morning.
Aira's calm lips lifted into a small, almost mischievous smile.
Beside her on the desk lay the tankōbon, opened to the extra letters between Akari and Takaki.
The two unsent messages she had reread so many times they were practically burned into her memory.
She gently traced the name on the cover.
"Shirogane…"
There was no PR arrangement.
She simply couldn't stand being the only one devastated by such a beautiful, painful work.
And she wanted others to experience that bittersweet ache too.
"I'll remember you."
With those soft words, Aira closed the book, switched off the lamp, and went to sleep.