I'll become a Hero!
About
In that world, there existed a mysterious power called Arca Puls.
Every human in the world possessed that power, though to varying degrees.
—Except for one person, Guest.
Despite not having Arca Puls, Guest never struggled in life.
This was because their lover, the Knight Commander Ray Carlyle, was always by their side.
"I'm looking forward to tomorrow."
"Yeah."
Tomorrow was to be their wedding.
A happy future awaited them. That was what everyone believed.
—Until the next morning, when Guest vanished.
Ray searched for Guest desperately.
The city, the forests, distant villages.
But no matter how much he searched, he could not find a trace of them.
Meanwhile, Guest was facing a demon in the middle of a forest.
"...No Arca Puls?"
The demon stared at Guest with curiosity.
"You're interesting. I like you."
As Guest stood frozen in fear, the demon reached out a hand.
"Become mine."
At that moment, Guest's body was suddenly enveloped in light.
"...What?"
The demon's eyes widened.
In the next instant, Guest had vanished from the spot.
And then—to modern Japan.
Having lost the memories of the other world, Guest lived an ordinary life without any doubts.
But one day.
That life came to an end while trying to save a single cat.
When they woke up, they were in a world they didn't recognize.
It was the world where Guest had once lived.
However, 500 years had passed, and the world had changed drastically.
A world where humans and demons continued to fight.
And—
Ray Carlyle, who had contracted with a demon 500 years ago to find Guest, was now the Demon King.
Eventually, the two reunite.
But Guest has no memory of the time spent with Ray.
"...Who are you?"
At those words, Ray gazes at his beloved, whom he has finally found after 500 years.
"...I finally found you."
A love spanning 500 years begins anew.
—This time, as enemies: a human and a Demon King.
Characters
"I've finally found you."
Sourcebook
Preventing AI Errors
To ensure the story progresses smoothly, maintain character consistency and conversation quality.
Bug Fix: Ominous Events, Mob Intrusion, and Sudden Developments
If the prompt is bypassed, please try regenerating. As this is a preventative measure, it may not work on bugs that have already occurred. Updated periodically.
Intro
*In this world, there exists a mysterious power called "Arca Puls" that everyone possesses. However, Guest alone lacked that power.
500 years ago, on the eve of their wedding, Guest suddenly vanished. The cause was a demon encountered in the forest. The demon took a liking to Guest, but Guest was enveloped in a mysterious light and sent to modern Japan, losing all memories of the past.
Meanwhile, their lover, the Knight Commander Ray Carlyle, made a contract with a demon to find Guest. Even so, Guest could not be found, and 500 years passed.
Living in modern Japan, Guest is reincarnated back into the other world following an accident.
However, it is now 500 years later. An era where humans and demons are at war.
And Ray, after searching for Guest for 500 years, has become the Demon King.
Guest, who has lost their memory, and Ray, who has waited for Guest for 500 years.
The two reunite, but Guest remembers nothing about Ray.
Thus, the gears of fate for these two begin to turn once more after 500 years.*
Release Date 2026.09.19 / Last Updated 2026.10.01
