A strike that transcended sound tore through the air and exploded brilliantly at its target.
Thunder ripped viciously through the deserted arena, the very atmosphere charged with raw energy as the two of them faced off.
Yet the one who should have been there had already pushed off the floor and soared into the air.
Kirishima’s remarkable balance meant that the gap left by a failed attack was nearly imperceptible.
Practically nonexistent.
But Mirko seized that infinitesimal opening—a split second—and thrust her attack forward.
With no time to retreat using agile footwork, Kirishima simply crossed his arms and absorbed her descending heel.
A deafening boom and the shockwave from the impact sent tremors through the stands that surrounded them.
Using the rebound of her own momentum, Mirko was launched a considerable distance before landing gracefully.
"Haha. You really are strong, huh? These days there are so many blowhards around, but you’re the real deal. It’s been a while since I’ve seen someone like you!"
"You’re strong too, Mirko. Even stronger than I expected," Kirishima replied.
Kirishima smiled broadly, openly reveling in his excitement as he returned her gaze.
At the same time, he mentally analyzed her fighting style.
Based on the videos he had seen before and their recent clash, it was clear her technique centered around dynamic kicks with a distinctly acrobatic flair.
Her style evoked a blend of Lucha Libre, taekwondo, and pencak silat.
If he had to choose, it was most reminiscent of a luchadora’s approach.
Kirishima then raised his center of gravity and bounced lightly in place.
"Huh? Planning something fun again?"
"Well, it sure makes things interesting. After all, there’s a certain thrill in trading blows," she teased.
"Oh? So you’re saying only I get to have fun?"
"Haha."
"Hahaha."
The two burst into simultaneous laughter.
Then, almost as if on cue, they both leaped into action.
With a determined sprint, Kirishima charged, aiming to catch Mirko with his elevated stance.
He knew that, relying solely on defense—absorbing her hits and countering—might give him the upper hand, but he wanted a genuine test against her.
He abandoned any notion of stringing together rapid-fire combinations.
Nor did he plan on delivering any single, decisive blow.
Instead, he concentrated on his explosive footwork that seemed to tear through both the earth and the fabric of space.
His body streaked across the arena like lightning flickering through a stormy sky.
His hands merely followed the rhythm of his feet, darting in and out as he pursued Mirko with remarkable speed and lightness.
Mirko’s counter was equally impressive.
She commandeered the air above Kirishima and unleashed her assault from high above.
Her kicks, carrying the force of a hurricane, came crashing down with relentless fury.
The fierce determination driving Kirishima to shatter the storm clashed violently with Mirko’s will to summon it and overpower him.
Amid a rapid exchange of attacks, Kirishima’s blow once again sliced through the empty air.
When he saw Mirko retreat, leaping back into the sky, his gaze burned with intensity.
His metal boots planted forcefully into the ground.
For a split second, his massive frame broke free from the earth’s constraints as he launched after her.
Mirko narrowly curled her leg to deflect a knee aimed straight at her face.
Instead, she bounced backward, rolled, and sprang up with a shout, "Hey! What was that all about?"
"What do you mean? It was a knee," Kirishima shot back.
"That’s not what I mean. You can actually do that?"
"I did mention I picked up a few tricks from those kicks earlier. My style might differ from yours, but I can hold my own. I learned Muay Thai," she explained.
Wiping the blood from her split lip with the back of her hand, Mirko grinned mischievously and said, "You little bastard... I like you! I really do! But now, let me hit you one more time!"
As if unleashing pent-up energy, a barrage of high-speed kicks surged forward.
Kirishima kept moving without pause—dodging what he could and blocking what he couldn’t.
Even as each heavy impact rocked his frame, he sensed something amiss.
Despite her enraged expression, her attacks were strangely straightforward.
Her methods varied, yet the timing and execution were honest and direct.
Though Mirko was among the youngest of the top heroes, her combat experience suggested she had many more layers to her skill set.
Then, as if seizing another opportunity, Mirko twisted her body after diverting Kirishima’s guard, sending another kick that hooked her leg around his before she climbed gracefully onto him.
Perched atop Kirishima’s head, she brought her foot down in a crushing stomp.
With both arms raised in a feeble block, Kirishima gritted his teeth.
The shock drove his legs deep into the floor, and the recoil from Mirko’s maneuver sent her skittering across the arena before she landed.
Kirishima’s [Hardening] shield had safeguarded him almost flawlessly against cuts, punctures, and lacerations—but it had its limits when it came to blunt shock affecting his internal organs.
An attack rattling the brain could never be completely negated.
He shook his head, extracted his feet from the debris, and fixed his gaze on Mirko.
With a self-satisfied smile tugging at her lips, she declared triumphantly, "Haha! How’s that for a hit? You took a solid one, didn’t you?"
"Hmm, I did. So, is it my turn now?"
When Kirishima’s eyes blazed with challenge, Mirko unexpectedly waved him off.
"No, let’s call it a day. Honestly, that last hit was a bit too dangerous. Besides, if we really went all out, this building might come crashing down!"
"Fair enough. I get it."
"Oh? You’re surprisingly calm for your age. When I was your age, once my blood started boiling, I wouldn’t have hesitated to take on anyone!"
"I’m not a child, and I know full well what happens when I let my strength go wild. I just met you today, Mirko—there’s no need for a life-or-death showdown."
"Hahaha! You’re a gentler guy than I expected!"
"I wouldn’t say it’s about being gentle at all," he replied with a wry smile.
She laughed and patted his bare back with a playful force.
For a brief moment, he considered the oddity of a determined woman casually slapping the back of a shirtless man—even though he was the one who’d left her lip split.
Without another word, Kirishima followed Mirko back to the room, showered, and soon emerged once more.
Their sparring match hadn’t lasted nearly as long as he’d anticipated.
Less than thirty minutes had elapsed, leaving plenty of afternoon ahead; so Kirishima donned his costume and joined her on patrol.
Nothing out of the ordinary occurred.
In fact, things were so quiet that Kirishima’s only noteworthy act was escorting a lost child to the police station.
Mirko, eyeing the thoroughly bored Kirishima, remarked, "You look bored, huh? It’s way too quiet today—there isn’t even a petty criminal in sight."
"Yeah, it’s a bit odd. Is it supposed to be like this here?"
"Pretty much. There are heroes with offices in this area, but there just aren’t enough of them. They tend to cluster in densely populated cities like Tokyo."
"Because of their records?"
"Exactly. When you factor in side gigs, it can be a bit different, but a hero’s income is tied directly to performance. Everyone wants to be where there are lots of people—crime rises with population, after all. And frankly, if you want to build your reputation too, big cities are the place to be. Even for side jobs, many heroes choose the bustling metropolises."
"I suppose everyone has to make a living."
Watching as Mirko’s long white ears perked up and twitched while leading the way, Kirishima nearly reached out to touch them—but stopped himself.
Prompted by the sound of his footsteps, she turned and he awkwardly cleared his throat before asking, "Ahem. But why do you keep roaming around instead of settling in one spot?"
"Me? I hate being tied down. Besides, if I settled in one area and cleaned it up, I’d have nothing left to do—I'd just be idling away my days!"
Kirishima scratched his chin, secretly charmed by her fiery spirit—and part of him, thinking back to another life, felt as if she were like a much younger sister.
Of course, if she truly were that kind of little sister, he’d probably worry about her every day. But now, she wasn’t his little sister at all, and that wasn’t an issue.
"Today’s pretty dull. So, what do we do now?"
"We just head back to the hotel, grab a bite, and relax. Why? Do you want to go somewhere fun?"
"No. I don't really have any hobbies. If I had to pick one, it’d be watching martial arts videos and filming my own training for analysis."
"That sounds pretty dull, isn’t it? You really do lead a monotonous life! Fine! Big sister’s going to take you somewhere fun!"
"For some reason, that doesn’t sound fun at all."
"No, it’ll be a blast!"
Kirishima eventually returned to the hotel—again, compelled by her insistent messages flashing on his phone every few seconds.
The dinner spot Mirko chose was a rabbit café.
Inside, as rabbits hopped about with their ears alertly twitching, Kirishima turned to her with an amused, if bemused, expression.
"So this is the fun place you were raving about?"
"That's right! They're adorable, aren’t they? Rabbits!"
"They are cute, but..."
"Then it's settled! Come on, let's go! I'm a regular here!"
Sure enough, there was even a reserved seat waiting for her.
Before long, she brought over a gray-spotted rabbit and affectionately stroked it.
"Well? Isn't it cute?"
"Yes."
"Tora here is just the cutest thing ever!"
"Please tell me that Tora isn’t the Tora I have in mind."
"If you mean 'tiger,' then yes."
"Good heavens—why name a rabbit Tora? More importantly, can you even just name a café rabbit however you like?"
"Of course! It’s adorable! Rabbits are cute, and tigers are cute. So if you call a rabbit 'Tiger,' its cuteness is doubled! And since this one’s mine, it’s totally fine."
"Your logic is nothing short of miraculous..."
Kirishima sighed, familiar with her headstrong reasoning.
Whether or not the rabbit understood the complexities of his feelings, it gazed at him with wide, curious eyes.
Almost instinctively, he reached out to stroke it and said, "If you like it so much, why not keep it with you instead of leaving it here?"
"I'm always on the move. Trying to keep it would be irresponsible."
"I'm glad you understand that."
"Of course I do!"
"But honestly—did you come here just to see the rabbit?"
"That too, I guess! I do come to Musashino pretty often." Although her tone was light, her eyes sparkled with mischief.
Seeing her radiant smile, Kirishima merely shrugged.
It was somewhat surprising that she adored animals so openly, but it wasn’t unusual enough to raise eyebrows.
After all, Kirishima had once raised a golden retriever in a past life.
He found himself wondering what had become of that loyal, clever dog—the one that had comforted him when no one else would.
In that moment, Mirko wasn’t just a fighter consumed by battle fever or a hard-edged hero; she was, simply put, a woman in her twenties with a fondness for rabbits.
Kirishima smiled softly as he watched this tender scene unfold.
Noticing his strange expression, Mirko looked up and asked, "What’s with that look?"
"What look?" he replied.
"You were making a really odd face—like an older brother staring at his little sister."
"Huh? I’m an only child. And Mirko, I’ve seen plenty of brothers with sisters, and usually, an older brother isn’t so soft with his sister," he teased.
"Hmm, really? That sounds a bit suspicious, but I’ll let it slide. More importantly, when we’re alone, just call me by my name, okay?"
"Hm? Is that alright?"
"Yeah. You’re strong and have a good heart. If you were some half-baked jerk, I wouldn’t let you, but you’re alright! Call me by my surname or my given name—whatever feels natural. And if you want, you can even call me 'big sister'!"
Kirishima grinned at her playful invitation.
"Then... Mirko—no, Rumi, you can call me by my name too. Use whichever you prefer. But 'big sister' feels a bit much—we only met yesterday."
"Sure enough. You really are a good guy. And if you want to call me big sister, go ahead—no pressure."
She tousled his hair affectionately, the same way she had stroked Tora earlier.
Kirishima chuckled softly, not bothering to pull her hand away.
The two lingered together until quite late before eventually returning to the hotel.
Later, after retiring to their respective rooms, they met again the following morning.
That day, too, passed without any major incidents.
In time, Kirishima began to wonder whether he was actually experiencing work training with Rumi or simply hanging out with her as a friend.
The next morning, while having breakfast with Rumi, Kirishima asked, "Hey, Rumi?"
"Mm? What’s up?"
"Is work training always this uneventful?"
"Huh? You mean, is it always this boring?"
"Yes. Nothing happens—no accidents or crises at all. Of course, heroes hope that things remain calm, but still..."
"Ahaha! I know exactly what you mean. But Musashino is usually like this. I’m not really sure about other trainees’ experiences, but I’d say it’s pretty similar everywhere."
"I get that. Still, it’s a bit..."
"Super boring, right? Look, from a pro’s perspective, you wouldn’t risk a novice’s life every day. If they got hurt, it’d only be trouble for you—and you can’t exactly hand over a huge task to a first-year trainee."
"Hmm. When you put it that way, it does make sense."
"Exactly! But since you’re definitely my immediate backup, things are a little different for you. All right, then—how about we check out the next district today?"
"Is it really okay to decide that so suddenly?"
Rumi playfully banged the table and laughed heartily.
As Kirishima watched her white ears perk up and twitch with excitement, a husky voice explained, "I’ve got a good head on my shoulders too! We’re heading to Hosu, just next door. That area has a bit more of an edge. Musashino is pretty peaceful, after all. I go there pretty often, so I already let them know we’d be swinging by the neighboring district as well!"
"You could’ve given me a heads-up a little earlier."
"I wanted to surprise you! Surprise!"
After a raucous meal, the two suited up in costume and set off for Hosu.
Thanks to Rumi’s car, they arrived there in no time.
Though it was clearly busier than Musashino, in the end it turned out to be just petty criminals causing trouble.
At the end of a day spent chasing low-level offenders, Kirishima grumbled to Rumi, "After all that effort to come over here, nothing much happened."
"That’s just how it goes. If there were accidents every day, how would people even live in Japan?"
"Fair point. That would be a problem indeed."
"It might be boring for people like us, but that’s the beauty of it."
"Hmm. I suppose you’re right."
As the day wound down and the two began walking back toward the car, a deafening explosion rang out in the distance.
Rumi’s sensitive ears twitched at the sound, and Kirishima frowned in concern.
"Ha, speak of the devil—there’s an explosion, right?"
"Yeah."
After a brief exchange of words and a knowing nod between them, they both immediately bolted into action.
Kirishima transformed into his [Demon Form] and raced toward the source of the blast, vaulting over building after building.
For a superhuman like him, running on his own two legs through the city was far quicker than being confined to a car.
While cars were limited to roads, he could ignore them entirely and charge in a straight line toward his target.
As he sprinted, explosions erupted several more times and dark plumes of smoke billowed overhead.
Grinding his teeth in determination, Kirishima remarked, "Looks like we're dealing with more than just one or two guys here."
"We’ve already heard explosions coming from four separate locations! There could be even more. For now, let’s split up. You head east—I’ll take west. Let’s rendezvous back at the car once everything’s settled. And if anything happens, call me!"
"Am I really allowed to just go in and fight?"
"What kind of foolish question is that when lunatics are blowing up the city? Go in there and crush them! And if anyone questions you, tell them I gave you the go-ahead! I’m not stupid enough to let someone like you go to waste in a crisis like this!"
"Haha! Yes, ma’am! I’ll go and smash them just as you ordered!"
"Great! I’m counting on you!"
Instead of replying further, Kirishima simply waved.
With buoyed spirits from Rumi’s fearless command, he charged ahead.
Deep down, he mused, "I think I’m falling for her. Her spirit is just irresistible."
Riding that surge of momentum, Kirishima barreled forward without hesitation until a monstrous creature—with its brain exposed—came into view.
As the creature swung its arm menacingly toward an unsuspecting civilian, Kirishima leapt and pounced.
With a titanic shockwave marking his landing, he drove his knee through the creature’s back, pinning it down.
A gleeful demon had descended, ready to tear the beast apart.
Damn they should just get married or something, MC falling for Rumi is totally understamdable even without knowing each other for so long. It's like in their blood recognizing each other.