The Return of Mortal from Another Realm

I don't know how this could happen.

"Nee~... How long will you keep daydreaming?" a woman's voice next to me exhaled a warm breath after saying that.

"I-I..." I stuttered in my speech.

"Isamu!" another woman to my right said firmly, embracing one of my arms.

"Y-yes?" I still responded hesitantly.

"I-samu, can I do it first!" Another woman stood at my stomach. My situation was quite dire, somehow trapped between these three aroused women. How did this happen, and it all started three months ago.

...

Three months ago...

"Haah... If only I had accepted the Emperor's gift, I wouldn't be suffering like this upon returning," a young man complained as he walked toward his school.

The teenager was 17 years old, with red hair touched by hints of black. Like a burning flame, his sharp eyes reflected courage, and his athletic body radiated strength.

He was walking back home after leaving it for a year. Strange events had happened that day; he was summoned to another world. Specifically, the young man, named Isamu, was summoned to a different fantasy world. At that time, he didn't know the exact cause.

However, a few days later, the truth was revealed. Isamu realized he was merely a food, manipulated to grant more power to the individual who summoned him.

In the other world, humans from Earth were often considered weak. However, in summoning rituals like this, when humans from Earth were called to another world, they had to traverse the realm of the rift. This process would overhaul their bodies, adapting them to the target world's reality as they were directly exposed to cosmic energy. This was why the bodies of humans from Earth held high value there.

Hence, approaching the summoning ritual in the alternate world, Isamu chose to escape. Through a grueling struggle, he managed to defeat the one who summoned him, sever the link, and collapse the portal connecting the two worlds.

According to the plan, Isamu should have been absent for a year on Earth, yet he returned right at the moment he was summoned. Time in the Earthly realm seemed not to apply to him. This reinforced his theory that the alternate world he was summoned to existed on a higher dimensional plane than Earth itself.

However, despite Isamu successfully returning to his own world, he couldn't feel the relief he hoped for. His journey in the alternate realm left a mark on him. Those who struggled there, the sacrifices he made, it all weighed heavily on his mind.

"Even so..." Isamu stared at his rough palms due to the battles. "I managed to return, and that's satisfying, even though the power I gained from that world isn't truly useful in this world." His thoughts flowed as he clenched his fists.

At the moment, Isamu was walking towards his apartment. He lived there alone, as his mother worked abroad as a professor at a private university, and his father had passed away when Isamu was 5 years old. This was the reason he wanted to come back from the world that had given him so many experiences and emotions. Isamu didn't want to leave his mother alone, especially because he was an only child and the sole remaining family member.

As he passed through the park on the hill, with the sunset clearly visible amidst the city's hustle and bustle, Isamu felt this place as a source of serenity. This spot was strategic for him to contemplate and unwind after a day of studying. He often gazed at the reddening sky and the setting sun before heading home for real.

Now, after returning from the world that drained him, Isamu longed for that ambiance. He wanted to reflect and reminisce in the old atmosphere, like now, as a way to confront the complex feelings and experiences from his adventure in the other world.

He gazed at the sky until nightfall, and all the lights that illuminated gave life to the city during the nighttime.

"Ah, it feels relieving..." he murmured.

After a moment of nostalgia, Isamu intended to head home. However, his steps halted as he saw two women who seemed lost and bewildered on a park bench that faced the sunset from earlier.

"Strangers?" the hair of one of the women felt unusual for the Eastern region and her face looked unfamiliar to her.

Especially the other woman, who was shorter with striking silver hair.

"I know gathering together is impossible..." She said that with a complaining tone.

Although eavesdropping on someone's conversation wasn't polite, Isamu's curiosity and the suspicion that they might be lost tourists pushed him to offer help.

The shorter woman next to her looked at Isamu with a worried expression. "We're just unlucky because they turned out to be Heroes. With the help of someone else, I'm sure—"

"No, Maria... let's put an end to all this deception." The red-haired woman shook her head, cutting off Maria's words.

Isamu pondered, 'Hmm, deception? Are they a group of swindlers?' His mind raced, and he decided to keep his distance to avoid coming across as a stalker. He employed the ability he acquired during his time in the other world. [Infiltration] This ability made him feel like a ninja, where his presence became extremely faint. Even beings of high threat level would find it difficult to perceive him. However, he was aware of the weakness of this ability. If he was detected even once, the ability would become useless and easily overcome by his opponent.

"I understand... I will obey your words, Mio-sama." The shorter woman, acting as a servant, didn't seem to mind. She clearly understood Mio's feelings.

With a gentle smile, Isamu heard the woman say, "That's what makes you kind-hearted, Mio-sama... I personally don't see a problem with deceiving humans who approach us with hidden motives."

"Perhaps…" Mio replied with a somewhat hesitant voice.

Mid-conversation, the two women suddenly sensed a change in the atmosphere around them, and Isamu also felt a magical incantation approaching him.

"Magic? Wait, magic exists on Earth? Seriously?" His mind was filled with surprise and doubt. He felt quite certain that what he had just sensed was the effect of magic. At the very least, it seemed like a barrier-type magic that could isolate an area from the outside world and trap targets within.

However, he didn't have time to be astonished because...

"Grrr..."

From behind a tree, Isamu could see and hear the growling of a manticore, a rare and fearsome mythological creature. Manticores had powerful lion bodies with bird-like wings and tails ending in sharp spikes. Their humanoid heads had sharp fangs and piercing eyes.

Isamu felt taken aback and stunned. This was his first time facing a magical creature like this directly. His mind spun quickly, trying to figure out what was truly happening. However, the sensation from the earlier magical incantation, along with the presence of the manticore, made him realize one thing that shook his beliefs.

The supernatural wasn't just present in other worlds, as he had experienced in his adventure there, but it also existed in his world, on Earth. The manticore and the sensed magical incantation were proof that his world held unexpected magical elements.

The sense of surprise and wonder towards the newfound magical creature still filled Isamu's mind. However, amidst it all, a new curiosity and enthusiasm were growing within him. And all these clues seemed to be connected to the two women he saw in the park, who were linked to the world of magic he had just realized. As his focus returned to the two women, a sensation appeared before them.

What emerged from the shadow were three unpleasant figures. This atmosphere gradually changed form.

Without a doubt, they were demons. What made Isamu sure was that the humanoid figures possessed demon characteristics, such as horns and bat wings.

"Is that so... I didn't expect you to come willingly."

Mio glared challengingly at the three [foes].

Her voice quivered slightly. It wasn't out of fear. But out of—anger.

Isamu was still observing at this point, his presence still unnoticed even by the Manticore right in front of him.

"Unforgivable... I will avenge my parents...."

Needless to say, this woman called Mio had strong ties to demons, probably even being of influential demon lineage. Then, how could she be targeted by assassins if she wasn't someone important? There must be something, and Isamu believed it could influence the future.

"Eliminate all humans... Alright, let's go."

Mio narrowed her eyes to focus on one thing: magic.

"Prepare yourself... I'll kill you a hundred times."

As she said that, Mio's body emitted a red aura. She unleashed her own magical power.

The surge of magic emitted by the current enemies was pitch black, darker than the night.

So when he learned how to use his magical powers from Maria, her aura wasn't black, wasn't blue, but red—brighter even than blood. A deep red color that burned unforgivable enemies to ash.

"—Okay, let's begin."

Special abilities like magic basically didn't exist in this world. Ordinary humans couldn't perceive such phenomena. Therefore, they couldn't interfere here. And—Mio's words were the sign that the battle was about to start.

Two [shadow] manticores approached them simultaneously. In this coordinated movement,

"Eat this!"

Mio released her attacking magic. A flash and an explosion sounded simultaneously. Lightning magic fell from the sky. But both shadows exploded, penetrating the dust created by the attack.

Manticore. These intelligent magical beasts must have avoided the lightning.

...What about the scythe guy...

He couldn't feel the enemy's presence anymore within the billowing dust. He must have been defeated by the lightning magic. If that's the case, Mio redirected her senses back to the two magical beasts.

"Mio-sama, I'll take care of the next one."

Maria beside her kicked the ground and flew forward, blocking the manticores. However, it was a disadvantaged two against one situation, with a considerable physical difference.

'Yeah... I should have bought popcorn before coming here!' Isamu thought, just watching the battle. The reason he did that without helping at all was that he needed to assess the situation. If necessary, he would help; if not, he would remain silent.

He couldn't feel the enemy's presence anymore within the billowing dust. He must have been defeated by the lightning magic. If that's the case, Mio redirected her senses back to the two magical beasts.

"Mio-sama, I'll take care of the next one." Maria beside her kicked the ground and flew forward, blocking the manticores. However, it was a disadvantaged two against one situation, with a considerable physical difference.

"———" The manticores, deciding to eliminate Maria as an easier target, quickly scattered, aiming their attacks from the sides. One manticore came with its fangs, the other with its claws. Coordinated attacks from various directions. Maria could only retreat to avoid these strikes. But...

"Ahahaha, how foolish."

With a laugh on her lips, Maria leaped forward. She aimed for the right leg of one of the attacking manticores. As she closed in, she grabbed the creature with her hand and with a swift motion, swung her fist toward its head.

—Unlike Mio, Maria lacked skills in offensive magic.

So how did she fight? She answered with roars and punches. The manticore that received Maria's punch fell, leaving a hole in the ground. In the pit, the manticore lay motionless, losing its form. Maria looked down at the remnants of the creature and let out a contemptuous breath.

"That's all... Quite boring. Please provide a more exciting challenge that'll make me sweat."

Then, she shifted her gaze to the next target.

However, the magical creature approaching Maria from the right suddenly changed direction, heading towards Mio. Mio remained still. The creature's sharp claw swung down towards Mio.

KEEEEEK! However, with a sound akin to metal clashing, the claw was repelled. The ferocious attack of the magical creature was thwarted by the transparent barrier that Mio had placed beforehand. Mio raised her right hand toward the manticore.

"It's over now— Die a hundred times and try again."

As she calmly spoke these words, a red light sphere created by Mio struck the creature directly. After an explosion, no dust remained.

"Are you alright, Mio-sama?"

After Maria's shout from a distance, Mio nodded with certainty.

'Hmm~... Well, it seems like they don't need my help,' Isamu thought, observing their powers with admiration. Although their magic was quite impressive, it seemed that they weren't as powerful as the sorcerers in the other world. Their magic focused more on large-scale damage and improvisation in battle. However, this was just an initial assessment. Isamu realized he hadn't fully grasped how magic operated in the world of Earth.

"—Oh, it's better we leave this place."

After defeating the enemies, the magic that restricted human access should have been lifted. The place was now in chaos due to Mio and Maria's attacks. If someone passed by and saw this scene, they would surely report it.

However, before they left...

Mio's final gaze turned to the view of the city at night. The sight she should have seen together with a little child.

—It was the beginning of everything.

"Mio-sama!"

As she turned around at Maria's shout, a [shadow] appeared before her. A creature that should have been defeated by the earlier lightning attack. Its hands glowed with dark magical power.

"Enough already~" Isamu's voice broke the silence as he jumped forward, intercepting its attack and pressing its head firmly into the ground until the earth shattered.

Mio and Maria both looked puzzled, gazing at the sudden appearance of a stranger who came to their aid. Although they felt assisted, they remained wary as the man's motives were still unclear to them.

"Kuh—... Who are you!" Despite being injured, the creature was still alive.

"M-me?... Um~" Isamu pretended to think for a moment. "Ah, right, I'm someone who's returned!" Isamu said, smiling, and launched an attack.