That afternoon's classes passed as usual.
Nothing out of the ordinary occurred—at least on the surface.
The only noticeable difference was Yukino Yukinoshita's slightly unnatural behavior. She seemed distracted, her reactions slower than normal. Still, this was something that could be adjusted with time.
As for Kisaragi Akira, nothing unusual happened to him.
School ended.
He went home.
After lying down on the sofa, Akira casually opened the Doomsday Chat Group.
The moment the interface appeared, he realized the group was unusually lively.
March 7th:"Saeko, how are things on your side?"
Saeko Busujima:"The school is in complete chaos, but I'm with a few classmates right now. It's relatively safe."
Exusiai:"I think it's better to stay away from schools. There are way too many people."
Saeko Busujima:"I agree. We're already planning to escape. On the way, we'll try to find our friend's parents."
"…?"
Akira frowned slightly.
Something had clearly happened in Saeko Busujima's world.
Could it be… a zombie outbreak?
Unknown:"@Saeko Busujima, what happened exactly?"
Saeko Busujima:"Akira-kun… just like you warned before, a zombie-like virus has broken out. Humans are turning into undead. Thanks to your reminder, I managed to make some preparations in advance."
Unknown:"…"
So it was true.
Exusiai:"Akira, can you predict the future?"
Kisaragi Akira:"Sorry to disappoint you. I'm not a fortune teller. I can't predict the future—I just have some basic information."
March 7th:"Don't say that, Saeko! If you need help, just say the word. This girl will help however she can!"
March 7th:"That's right! I can even buy another gun from Esté!"
Kisaragi Akira:"Little March, thanks again for the gun. It was extremely useful."
March 7th:"Hehe."
Akira was about to ask for more details when the chat group system interface suddenly appeared.
[The Doomsday Chat Group has detected a Future Apocalypse in member Saeko Busujima's world.][Initiating Apocalypse Together Mode.]
[Apocalypse Together]: Three's Company[Duration]: 5 Days[Companions]: Saeko Busujima, Exusiai, Kisaragi Akira[Mission Directive]: Eliminate as many undead entities as possible.
[Upon activation, all companions will be transported to Saeko Busujima's world.][Time will be frozen in each participant's original world during travel.]
Saeko Busujima:"This is…?"
Exusiai:"Does that mean I can go to Saeko's world and help her directly?"
March 7th:"Whoa—amazing! Traveling between worlds like this is even cooler than a star train crossing the galaxy!"
Aqua:"Huh?! Why wasn't I selected? This goddess specializes in dealing with undead creatures!"
Unknown:"…"
[Do you wish to begin the journey immediately?]
To be honest, Akira hadn't expected the Doomsday Chat Group to possess such functionality.
This was no longer just a communication platform.
It was a mutual aid system—one that could directly intervene in apocalyptic worlds.
Kisaragi Akira:"I'm ready to go."
Exusiai:"Oh! I need to stock up on more etched bullets first!"
Akira confirmed the transfer.
A swirling, pitch-black vortex appeared in front of him.
"A portal…? A teleportation gate?"
Without hesitation, he stepped inside.
For a brief moment, the world spun violently.
Then—
Light returned.
When Akira opened his eyes, he was no longer at home.
He looked around.
A rooftop.
Suddenly, another dark portal opened nearby.
A beautiful red-haired girl stepped out.
She wore a short, asymmetrical skirt and held a firearm resembling a high-powered assault rifle in her right hand.
More striking than the weapon were the halo floating above her head and the fragmented, luminous wings on her back.
"Hello!" she said brightly. "Are you the boss?"
"…Boss?"
"Haha, sorry. I'm just used to calling commissions that," Exusiai said, scratching the back of her head.
"Just call me Akira," he replied, extending his hand.
"Exia."
She gently shook his hand.
Exusiai then began inspecting him curiously—up and down, left and right.
"You don't have any obvious distinguishing features. Are you an Agor?"
Akira gave a wry smile.
"I'm not Agor. Humans in other worlds are different from those in yours."
"Actually, many people in your world would probably be considered 'aliens' by humans elsewhere."
"For example—you look like an angel."
"Wow, that's a pretty weird setting," Exusiai muttered, scratching her head."But… I guess it works."
They looked down from the rooftop.
Below them, the campus had become a living hell.
Undead bodies wandered aimlessly. Blood and chunks of flesh littered the ground.
It was utter devastation.
Yet Exusiai showed no fear.
On the contrary—she looked excited.
"Brother Akira, should we go find where Saeko is?"
"No need," Akira replied calmly. "Follow me."
Before Exusiai could react, Akira lifted off the ground.
He simply manipulated the airflow.
With Primal Stone — Vector Manipulation (Level 4), controlling vectors like wind was effortless.
Just as he was about to fly away—
"Wait, wait!"
Akira turned back in confusion.
Exusiai pointed at herself.
"I can't fly!"
"…Ah."
He glanced at the small wings on her back.
Right.
Exusiai wasn't a true angel—she couldn't actually fly.
"…Ahem. Should I carry you?" Akira asked awkwardly.
"Yes! Yes! Hurry!"Exusiai's eyes sparkled as she nodded enthusiastically.
Akira landed and scooped her up in a princess carry.
She was surprisingly light.
And judging by her figure—quite well-proportioned.
Exusiai wrapped her arms around his neck without hesitation, looking full of anticipation.
"Let's go!"
They took off into the sky.
"Whoa! So this is what flying feels like? This is awesome! I love it! Let me take a picture!"
Exusiai shouted excitedly as Akira chuckled helplessly.
She really was an irredeemable optimist.