Multiversal Friendship System

"Alright… Let's begin."

Kurumi activated her "City of Devouring Time"—

—And began absorbing Souta's time.

The moment he was shrouded by the barrier, Souta felt as if his entire body had frozen.

His limbs became unbearably heavy, unable to move.

He couldn't even lift a finger.

Suddenly—

The cocky confidence he'd gained from becoming immortal instantly shrank.

His heart turned cold.

"Shit… Even if I can't die, I'm still completely powerless!"

Even if his body was indestructible, he was still just a weakling.

If someone dumped him into molten iron and sank him to the ocean floor, he wouldn't be able to resist at all.

He'd just be trapped in total darkness forever—his mind slowly spiraling into insanity.

"…Yeah, I should probably stay low-key from now on."

It seemed that even as an immortal, he still needed to be careful.

As Souta was lost in his thoughts, Kurumi finally breathed a sigh of relief.

"Thank goodness… no side effects."

In the end, her worries were completely unnecessary.

After absorbing two years from Souta, his body remained exactly the same—his skin looked just as healthy, he didn't lose a single hair, and he felt no discomfort at all.

It was as if nothing had happened.

"I told you not to worry."

Souta shrugged indifferently.

"Go ahead and keep going—this time, take five years."

Kurumi nodded.

"City of Devouring Time" activated again.

The barrier devoured another five years from Souta.

And yet—

He remained completely unchanged.

Seeing this, Kurumi gradually increased the amount.

Ten years.

Twenty years.

Fifty years.

A hundred years.

Two hundred years…

Reality Check: Infinite ≠ Instantaneous

Souta had a brilliant plan:

Since he was now immortal, he could supply Kurumi with unlimited time to use as she pleased.

But both of them had overlooked one crucial detail—

"City of Devouring Time" has a speed limit.

While Souta's time was indeed limitless (at least, as far as he could tell),

Kurumi's absorption rate wasn't nearly as fast as they had assumed.

Absorbing 100 years took her several minutes.

As a result—

The time-collection process became way longer than expected.

With no other choice, Kurumi ended up moving in with Souta.

Every day, they dedicated 12 hours to absorbing time.

The rest of the day was spent eating, sleeping, or going out for walks whenever Kurumi felt mentally exhausted.

And so, as time passed—

Kurumi's "Juice Extraction Technique" became smoother and more efficient.

At first, what took her several minutes now only required a single minute.

During this time, Kurumi also learned about Souta's situation in this world.

And in one simple phrase—

"No parents, no car, no house."

Orphaned at a young age, he grew up in an orphanage and became completely independent at 16.

Although he had been accepted into a good university, he chose not to attend.

Instead, he donated most of his income back to the orphanage that raised him—for several years.

"A genuinely kind person…"

But because of his "nice guy"(yasashii) personality, he had been taken advantage of countless times.

After being betrayed by people he once trusted, he fell into a depressive slump and quit his job.

Now, he survived by doing freelance work—writing game cheats and designing custom game maps for small commissions.

Basically, he had completely withdrawn from society and lived in his own little world.

Right now, Kurumi was the only friend he had.

After realizing this—

Kurumi couldn't help but feel a little smug… and a little happy.

"Hehe… I'd like to keep it that way."

"The Daily Routine of an Immortal and a Spirit"

Eat.

Sleep.

Extract time.

To outsiders, their life might seem boring and repetitive.

But in this simple and quiet routine,

Two months passed in the blink of an eye.

"How Much Time Have You Stored?"

One bright afternoon, Souta and Kurumi were sitting in a café, drinking coffee.

Leaning back against his seat, Souta lazily soaked in the warm sunlight.

Across from him, Kurumi sat gracefully, her elegant posture as charming as ever.

With a teasing smile, Souta asked:

"So, Kurumi, exactly how much time have you stored up?"

He took a sip of his coffee, then jokingly added:

"I feel like you're gonna drain me dry soon."

Kurumi's lips curved into a playful smirk.

She licked her soft, cherry-pink lips, then dragged out her words seductively:

"Oh my…? But I haven't even gotten serious yet, Souta~"

"A man shouldn't say he can't handle it, you know?"

Her sultry, teasing tone sent shivers down Souta's spine.

"…Okay, I give up. You're too good at this."

He had no chance against a pro-level flirt like Kurumi.

"Ahem… So, how much time have you actually stored up?"

Kurumi tapped her chin, then casually answered:

"Around two million years, give or take."

"Pffft—!"

Souta almost spit out his coffee.

"TWO MILLION YEARS!?"

"I had THAT much time to take!?"

Kurumi giggled at his shocked reaction.

"Indeed~ And yet, your time supply is completely bottomless." "The Elixir of Immortality certainly lives up to its name."

Hearing this, Souta rubbed his chin thoughtfully.

"Why do you even need that much time?"

Kurumi sighed softly, her voice tinged with helplessness.

"I don't really want this much… But traveling back in time with the 'Twelve Bullets' consumes an insane amount of time."

"Time is way less efficient than Spirit Energy(Reiryoku)."

Hearing this, Souta frowned.

"Time… Spirit Energy…?"

He quickly recalled some details from Date A Live's plot—

And suddenly, it all made sense.

Kurumi had killed over ten thousand people.

Even if she only absorbed ten years per person, that was over a hundred thousand years of stored time.

And yet—

She still couldn't travel back 30 years.

But Spirit Energy was a whole different story.

In Date A Live, Origami Tobiichi, after becoming a Spirit, once asked Kurumi to send her back in time.

Kurumi absorbed Origami's Spirit Energy—

And in one shot, sent her five years into the past.

If one Spirit's energy could send someone five years back—

Then traveling 30 years back would only require six Spirits' worth of energy.

"Holy crap… compared to Spirit Energy, time is absolute garbage!"

No wonder it had taken Kurumi this long to gather enough time.

Souta finally understood—no wonder Kurumi had been absorbing his time for so long.

"You should have enough time stored up to go back 30 years now, right?" Souta asked.

"Yes, and I even have quite a surplus. I won't say any more words of thanks, but know that I will remember this favor, Souta," Kurumi said, her gaze soft as she continued, "I plan to use the extra time for an experiment."

"Experiment?" Souta asked curiously. "What kind of experiment?"

Kurumi explained in detail:

"When I go back in time and change something, we don't actually know how fast the worldline will shift.

So before traveling back 30 years to erase Mio Takamiya's existence, I need to test it first. I'll go back two or three years, make a small but significant change, and measure how long it takes for the worldline to fully shift."

As soon as Souta heard this, he instantly understood Kurumi's reasoning.

Testing the delay in changes was absolutely necessary!

If they didn't know the exact timing, Kurumi might erase Mio Takamiya too quickly, and before Souta could pull her into his world, she might disappear from existence entirely due to the world's correction speed.