Son Si-woo and Han Ju-hee.
The reason these two, who initially detested each other, ended up getting married was simple.
The poor and the rich.
A swordsman and a mage.
A passionate personality and a calm personality.
For these two, who were mismatched in many ways, there was only one commonality.
That was, once they started something, they would never give up until they saw it through to the end.
Normally, if someone disliked another, one of them would avoid the other to prevent unnecessary conflict, but these two, on the contrary, sought each other out, escalating their disputes.
The reason?
Isn't it obvious?
Ironically, the more they disliked each other, the better they knew each other.
So, when one of them started to avoid the other, they could clearly see what the opponent would think.
‘They’ll think I’ve tucked my tail.’
‘They’ll think I’ve finally admitted defeat.’
That was the one thing they hated.
‘I can’t lose to that woman.’
‘I absolutely refuse to lose to that man.’
Their personalities, which would make them jump up in the middle of the night, screaming and raging if they didn't see something through to the end or achieve victory, kept drawing them back into each other's sight, even though they could have simply ignored each other.
And observation gave birth to new understanding and emotions.
‘That woman had that side to her?’
‘So she could say things like that too.’
Parts they hadn't known, or rather, hadn't tried to know, began to come into view one by one.
Each one was a good deed that improved their existing negative perceptions.
These sights diminished the intense rivalry they had harbored for each other, and in its place, new feelings began to blossom.
That was none other than affection.
After realizing their mutual affection, their relationship progressed at lightning speed.
Holding hands, kissing, spending nights together.
They eventually defied their families' opposition, succeeded in a wedding for the ages, had a child, and lived well.
Of course, that ending wasn't very good, but the point here was their tenacity.
A tenacity bordering on madness, where once they latched onto something, they couldn't let go until they were satisfied.
They had changed with the passage of time, but that one thing remained unaltered, even now in their old age.
"It's a success! The net's mesh size has shrunk to 1.8cm!"
"The real-time changes in the mana net's wavelength also yielded quite good results."
Han Ju-hee, who had been more interested in the offerings than the ritual itself, and Kim Do-jin, who had constantly been concerned about her.
Before they knew it, setting aside their emotions, they began to madly immerse themselves in the research, achieving results.
By the time they reached the tenth day of research, they had even achieved significant results.
They had succeeded in surpassing the performance of the best existing detecting artifact.
It was a half-success.
This was a product that could only be created through the painstaking manual work of Kim Do-jin and Han Ju-hee.
From a commercial perspective, it meant mass production was absolutely impossible.
But the two didn't care.
For them, only performance mattered.
Forgetting everything else besides the research, they talked endlessly.
"But there's still a long way to go. To reach the intensity you want, the net's mesh size needs to be 1.5cm... no, it needs to be almost 1cm."
"The patterns of the mana waves being emitted are still too simple. We need to incorporate more patterns..."
Even as she listed the problems they still needed to solve, a smile never left Han Ju-hee's lips.
Was it because of the slow but steady progress?
No.
‘I’m happy.’
She simply enjoyed the situation itself.
Doing magic research, to which she had dedicated her entire life, alongside the husband she loved, felt like a dream.
And just as much, she was afraid.
Because she knew that once this research was over, they would return to an irreversible relationship, as if nothing had happened.
It was truly a fleeting, dream-like moment.
She decided to put off thinking about the reality after waking up for as long as possible.
The cool-headed woman knew that the deeper she immersed herself in this situation, the greater the backlash she would experience upon waking.
But.
‘For now, I just want to be lost in this dream.’
She missed it to her very bones.
The moments they had talked so warmly, laughing with each other.
It felt as if the relationship, shattered by her own choices, was being pieced back together.
Even knowing it was nothing but an illusion, she couldn't shake it off and plunged deeper.
"What if we mix Earth-attribute mana into the net to further strengthen its connectivity?"
"Hmm... your opinion has a point, but in my opinion..."
"..."
So much so that she didn't even realize the affectionate, nasal tone, which she only used when calling her husband, not a stranger, was gradually seeping into the way she addressed him.
*
It was a continuous forced march.
Days where he would leave her to the research in the morning, go out for a brief training session, spend time handling tasks that absolutely required his attention, then immediately return and continue the research until dawn.
The time he spent sleeping was exactly one hour.
Even that wasn't for physical rest, but to recover his depleted mental energy.
After all, the bodies of S-rank Hunters could easily endure a month without sleep.
That was the result they achieved.
They strove to narrow the mesh of the mana net and diversify the mana patterns to effectively neutralize any attempts to break through it.
And one more thing.
"How about this?"
"What is it?"
"We shoot the mana net underground, spreading it widely. Then, if it surges from the ground to the sky, reading the surrounding information..."
"The accuracy would more than double, wouldn't it? But there will be a moment when the vertically and horizontally spreading nets overlap. How do we resolve the interference that will occur then?"
"Well, of course, you and I will have to figure that out starting now."
'Why? Surely you're not lacking confidence?'
It was a gaze that seemed to ask just that.
Normally, he would have bristled and rushed to solve the problem, but not now.
"..."
The longer the research continued, the stronger the sense of déjà vu that permeated his mind became.
A familiar sensation.
‘Where is this feeling coming from?’
The sensation, which he initially couldn't pinpoint where or when he'd felt it, gradually became clearer.
What tickled his chest was the way Han Ju-hee addressed him.
Dangsin.
It was a familiar term of address he had heard dozens, hundreds of times even in this body, but there was a distinct difference between how she used it now and how she used it before.
Tone, intonation, emotion.
The elements forming the word were blended in different colors and different forms.
And that form, too, was utterly familiar to him.
It was, yes.
The term of address she often used when calling him, her husband, back when they still loved each other passionately.
Her coquettish tone, which no one else in the world could hear, only he could.
Now, though faint, it was mixed into her words.
A deep question arose within him.
Why?
*
Pajukjise.
The most fitting four-character idiom to describe the speed of their research progress.
They relentlessly overcame the scattered problems, advancing until they finally reached the culmination of their research.
They succeeded in reducing the net's mesh size to under 1.5cm by utilizing the unique earth-attribute mana's inherent power.
They also succeeded in designing the mana wave patterns to be virtually infinite in generation and variation, fully incorporating the free movement of wind-attribute mana.
Finally, they not only had the horizontally spreading net but also added a net that shot vertically from underground to the sky, doubling the accuracy.
This was the result born from the combined talents of Han Ju-hee, who possessed deep knowledge of magic engineering, and Kim Do-jin, who could directly see mana and its flow.
She was certain.
"It would take at least 20 years for an artifact of this level to be commercialized."
The detecting artifact they had created with their own hands was 20 years ahead of the technology available on the market.
That wasn't an exaggeration or overconfidence, but genuine self-assurance, and in fact, her words were not wrong.
While it was still commercially terrible, the technology that realized it was a brilliant achievement, worthy of praise from every mage and magic engineer in the world.
As they neared the completion of their goal.
The expressions of the two grew darker, and their conversations dwindled.
‘It’s over now.’
It was because the time to wake from the dream was approaching.
Because it was time to leave the utterly happy moments and be thrown back into cold reality.
If it were up to her heart, she wanted to prolong the research in any way possible.
The thought of just closing her eyes and going for it had crossed her mind.
‘I can’t do that.’
She dared not give in to her impulses.
Because the moment she became any greedier, she might truly never see him again.
Eschewing any rash actions, she completed the final research with her own hands.
"It's finally complete."
One month.
The research, a period that could be considered long or short, had finally reached its end.
As initially expected, they created two types of results.
One was an area-of-effect artifact that periodically used detecting magic within a 1km radius.
The other was a personal artifact that used detecting magic within a 50m radius centered on the wearer.
If these two were distributed to bases and key personnel, nothing would be lost in vain.
"You've worked hard all this time."
"...You too, Hunter Han Ju-hee."
"Hey."
With the time for farewells imminent, she couldn't shake off her lingering feelings and made him an offer.
"To celebrate the completion of our research, how about we have dinner together?"
She thought it was a perfectly reasonable suggestion.
After all, hadn't she willingly dedicated her time to help him achieve his goal?
Wouldn't a single dinner be a sufficient reward for that?
Kim Do-jin, who had been gazing at her as she thought this, nodded and accepted the offer.
"Alright."
Barely suppressing the corners of her lips from rising, she walked ahead and said,
"There's a good restaurant nearby. Let's go there."
The place they arrived at was a restaurant they used to frequent.
It was a choice heavily influenced by her taste, but it was also a place Kim Do-jin had liked.
Except for one thing: the portions were small.
That's why whenever he came here, he would always eat two servings by himself.
"Three dinner courses, please."
Before he could say anything, she requested three servings.
"Is someone else joining you...?"
When the manager, who had come out to greet them personally, asked back in confusion, she shook her head and pointed at Kim Do-jin.
"No. Please bring two servings for him."
"Understood."
After the manager left with their order, she realized her mistake through Kim Do-jin's steady gaze and quickly made an excuse.
"Ah... the food here is good, but the portions are small. So I ordered two servings... Is that okay?"
"Yeah, sure."
Only then did Han Ju-hee let out a small sigh of relief as Kim Do-jin averted his gaze.
It was at that very moment.
"You noticed later than I expected."
Kim Do-jin spoke to her in a tone filled with certainty.
"I thought you, of all people, would figure it out much sooner."
"Y-you...?"
Hearing this, her eyes widened as if they would tear.