After settling on his internship, Tsutsumi dialed the number Mirko had left in her contact info. Normally, students reported directly to their hero's agency, but since Mirko didn't even have one, he had to set up a meeting himself.
"You already at U.A.?" Tsutsumi asked, a little surprised when she picked up.
"Principal Nezu told me about you. Meet me at Training Ground C." Her voice was blunt, and then the line went dead.
Exhaling, Tsutsumi slid his phone into his pocket and made his way over.
The simulated city was quiet when he stepped inside, streets lined with empty buildings. He glanced around, pulled out his phone, and sent her a quick message: I'm here.
The moment he hit send, a blur appeared behind him, a leg whipping toward his ribs.
Form Ride: Build! TankTank Form!
Her kick slammed into his blue tank-armored guard, sparks flying as the tracks ground against her shin, forcing her to hop back.
"Not bad," Mirko smirked, shaking off the sting. "Blocked my surprise kick. Good reflexes and defense."
"Isn't it a bit rude to attack a minor out of nowhere?" Tsutsumi said calmly, flexing the arm that had blocked the attack. "Aren't you worried I'll have you arrested?"
"That dry humor, hah, you really are like Nagant." Mirko's smirk widened. Nezu had clearly given her pointers on what buttons to push. "Guess it's no surprise. You're her son."
Tsutsumi's gaze hardened. "Tell me. What happened to her?"
"Nope." Mirko bounced lightly on her feet, smirk never fading. "You'll have to beat it out of me."
Tsutsumi's eyes went cold. He drew a card. "Build Up."
Form Ride: Build! RabbitRabbit Form!
His tank armor exploded off, replaced by sleek crimson armor. Mirko's smirk grew even sharper.
"That's the one," she said. "The rabbit armor. The reason half the internet kept tagging me in your clips."
Then both of them vanished.
Red and white blurs tore across the city. They clashed midair, legs colliding with a thunderous crack that shattered windows in every direction.
Mirko drove forward, appearing behind him for another strike. Tsutsumi twisted, their kicks slamming together and detonating another shockwave.
The simulated city shook with every impact.
A kick sent Mirko crashing through a tower of concrete, debris raining down as the building collapsed over her. A second later, she burst out of the rubble, grinning like a beast, and launched herself back at him.
Tsutsumi dropped low, one palm braced against broken asphalt as her heel cut through the air. He whipped his leg up in return, heel connecting with her face. Snarling, Mirko grabbed his leg and dragged him with her, both of them smashing through another high-rise in a storm of glass and steel.
They burst out the other side, panting, Mirko still grinning ear to ear.
"Not bad, kid. Maybe I'll call you up for workouts later on," she teased, stretching her jaw where his kick had landed. Property damage be damned, she was enjoying herself.
Tsutsumi's voice was flat behind his mask. "Are we done? This is going nowhere."
His body was somewhat numb. Drawn-out endurance fights weren't his style; he specialized in ending battles decisively.
"Tch! What's wrong? Too easy for you? Then let's kick it up a notch!" Her muscles coiled, veins bulging in her legs.
In a blur faster than before, she blitzed toward him.
"Luna Rush!"
Kamen Ride: Wizard! Hi-Hi, Hi-Hi-Hi!
Her kick collided with a glowing red magic circle, the shockwave blasting apart nearby buildings.
When the dust cleared, Tsutsumi stood in Wizard's coat and mask, purple eyes gleaming behind the red gem-like visor. With a thrust of his arms, six more circles lit up around them, one appearing beneath their feet.
Gravity spiked. Mirko was yanked downward, yet her body jerked upward at the same time, caught in a crushing pull.
"W-What the hell?!" she growled, only for chains to burst from the other six circles, wrapping around her limbs and body until she was cocooned in iron.
Tsutsumi exhaled and sat casually atop her struggling form, pulling out his cards and flipping through them as though she weren't thrashing beneath him.
Sometime later, he finally released her.
"Annoying brat," Mirko muttered, cracking her joints. "The rumors about you were right."
"You're just as bad," Tsutsumi said bluntly. "What responsible adult greets a student with a flying kick?"
She swung for his head. He tilted away effortlessly.
"You little punk. Keep that attitude up, and no girl's ever gonna marry you."
"You're not my mom." His reply was instant.
The two of them walked side by side, bickering, as other students gawked. It wasn't every day the number seven Pro Hero casually strolled through campus. Some fans even tried approaching her, but Mirko brushed them off with a wave.
"Not now. Gotta discipline this brat." She jerked her thumb toward Tsutsumi.
Eventually, they slipped out of U.A. only to be swarmed by fans waiting outside. Mirko cursed under her breath, then promptly grabbed Tsutsumi by the collar.
"Hang on."
And with a single leap, the Rabbit Hero carried him out of sight.
After some time, Mirko finally landed on a rooftop and dropped Tsutsumi onto solid ground.
"So, can you tell me about my mother now?" he asked immediately, wasting no time.
"Tch. Shouldn't you at least introduce yourself before throwing questions at me?" Mirko teased, one hand on her hip.
"Tsutsumi Ryoko. First-year student at U.A. Hero course. Code name: Decade." His tone was flat, straight to the point.
Mirko chuckled lightly. "Heh. You really do sound just like her." With a smirk, she added, "Usagiyama Rumi. Number seven Pro Hero. Hero name: Mirko."
Her grin widened as she looked him over. "Alright, brat. Since you'll be tagging along for a week, let's make it worth it. Nezu and your homeroom teacher already gave me the rundown, so here's the deal, you've got my permission to use your quirk in public. Just don't slow me down." Without waiting for a reply, she vaulted off the roof.
Attack Ride: Agito Tornador!
Tsutsumi summoned his hover bike in a flare of light and swung onto it, gliding down after her.
"Hey!" he called over the wind. "You still haven't answered me, what happened to my mother?"
Mirko went quiet for a moment as she bounded across rooftops. Finally, her tone dropped. "I don't know. She vanished after a mission one day. No word, no trace. If you want, I can poke the Public Safety Commission. They might have records."
Tsutsumi's gaze flickered forward. "…Thanks."
Their chase was cut short by the wail of sirens. Down below, a getaway car tore through traffic, police cruisers scrambling after them. Clearly a fresh bank robbery. By sheer chance, the two had stumbled right into it.
"Think you can keep up?" Mirko smirked, tilting her head toward him.
Tsutsumi raised an eyebrow. "Do we really need to run? I could end this from here."
She barked out a laugh. "Nope. If you just nuke it from a distance, the cops'll be left wondering what the hell happened. And then you look like the suspect, genius." Dropping into a low stance, her grin sharpened. "Try to keep up."
She launched herself forward, white hair streaming behind her as she charged straight toward the chase.
Tsutsumi stared after her for a beat, unimpressed. Then he pulled a card.
Attack Ride: Teleport!
In a flash of light, his body vanished and reappeared directly ahead of the getaway car, another card already in hand.
Form Ride: OOO! Sagohzo Combo!
Gray and silver armor locked into place with a heavy metallic roar. Tsutsumi raised one foot, then slammed it down.
The road buckled. A crushing gravitational pull tore the car to a halt, pinning it flat to the pavement. The criminals inside screamed as their bodies were dragged down by the sheer force, tires screeching helplessly until smoke poured from the rims.
Calmly, Tsutsumi strode forward. He grabbed the hood, tore the engine block straight out with his armored hands, and tossed it aside like scrap. Only then did he release the pull, the robbers slumping limply in their seats, too drained to resist.
A blur landed nearby. Mirko skidded to a stop, whistling low as she eyed the wreck. "Damn, you're even faster than I thought."
She peered at the groaning criminals. The gravitational crush had wrung them out so badly they could barely lift their heads. Her grin sharpened. "Tch. So you were holding back in our spar."
Tsutsumi gave her nothing in return, just silence.
That was when the police finally caught up, sirens cutting out as officers jumped from their cars. They immediately hailed Mirko, then glanced warily at Tsutsumi, recognizing him from U.A. but uneasy about his blatant quirk use.
Before they could say a word, Mirko waved them off. "Relax. He's with me. Kid's got my permission."
...
During that week, Decade and Mirko tore through city after city, darting from one hotspot to the next. Whenever reports of crime surfaced nearby, they didn't hesitate, they hit the scene head-on.
"Not bad, kid. You sure you don't wanna be my sidekick after graduation?" Mirko asked with a playful smirk, carrot between her teeth, her legs swinging lazily over the rooftop edge.
"Not interested." Decade replied flatly, chewing the rice from his bento.
"Oh, c'mon. You and I work great together." She leaned in, resting her elbow on his head like he was a stool.
He rolled his eyes. "You know, people are gonna start talking if we keep booking hotels every time."
Since Mirko didn't run an agency, and her own place was too far out, high-end hotels became their default stop whenever they needed to rest. The setup alone was enough to fuel rumors.
"They can think what they want. We're not doing anything wrong, so there's nothing to be afraid of." She brushed it off easily, then shifted gears with a grin. "So, excited for tonight?"
"Not really. Chasing a deranged Hero Killer doesn't exactly scream fun." His gaze stayed fixed on the city skyline.
Hosu City. For months, sightings of the infamous Hero Killer had been piling up here.
Mirko had actually planned to hunt him down herself before heading to U.A. to grab her intern. But after seeing Tsutsumi in action, and realizing he was more than the rumors painted him to be, she decided to slow her hunt and guide him instead.
"Relax," she said with a confident smile, smacking him hard on the back. "With what you've pulled off so far, this'll be a walk in the park."
Later that night, the streets of Hosu lay unnervingly quiet. Mirko and Decade prowled through the alleys, intent on tracking the Hero Killer.
But plans never last.
Without warning, chaos erupted as Nomu poured into the city, monstrous, gray-skinned things with exposed brains, the same nightmares that had stormed the USJ.
"Where's the hero!?" a boy cried, clutching his injured mother as one of the beasts lunged for them.
Final Attack Ride: F-F-F-Faiz!
A crimson photon drill tore through the Nomu's exposed brain, freezing it mid-lunge. Decade dropped in, slamming a flying kick into the other end of the drill, driving it clean through.
The monster screeched one last time before blue fire consumed its body, leaving nothing but ash on the pavement.
The boy gasped, then bowed his head in thanks. "Mister, are you a new hero? Who are you?"
Before Tsutsumi could answer, more Nomu staggered in, drawn by the death cry.
"Run. I'll handle this." Tsutsumi ordered. The boy grabbed his mother and bolted.
Attack Ride: Vertical Maneuvering Gear!
The sound of steel wires whistled through the air, then a Nomu's head spun clean off. Tsutsumi didn't even slow. He quickly realized these creatures were nowhere near as strong as the one at USJ; these were weaker copies, built for chaos, so he continued to cut off more and more Nomu's heads by the second.
[Mirko]: Decade, status?
[Decade]: Area's mostly clear.
Just as he slipped his phone away, a new ping lit up. Class 1-A group chat. Midoriya's message, his location.
One glance was all Tsutsumi needed. Midoriya was here, in Hosu, right in the middle of this chaos.
Knowing that the moss-headed idiot still couldn't control his quirk properly, Tsutsumi pocketed his phone and set off at once, straight for Midoriya's location.