u/RadiantImportance924

I'm hoping the formatting doesn't destroy itself on mobile. Enjoy!!

—

It's a normal weekend in central Musutafu, with families roaming the streets and parks. Kids are screaming and playing, parents are lining benches and sidewalks as they watch them play or talk amongst each other, there's a few street vendors selling yakitori and mochi.

Hinako is racing other kids on the playground, bolting at top speed with her tail whipping around to keep her steady. On the other side of the playground, in the grass, her brother Retsu is sitting with Raion. He's sitting with his eyes half-lidded as he watches his sister streak through the playground, sighing softly through his nose as he keeps one hand on the infant's head.

Their parents are lounging nearby; Kazumi and Denki are sprawled lazily on a blanket in the grass, studying the clouds while occasionally glancing at the kids. Katsuki is half on his phone, half watching Hinako. A keen eye ensures she doesn't cause public property damage due to a quirk misfire, and his leg bounces restlessly as his eyes dart back and forth. Aimi sits on a nearby bench with an iced coffee in her hands, her eyes fixed on Raion as she takes the occasional sip.

Denki and Kazumi are chattering on, commenting about one thing or another while Katsuki chimes in with the usual abrasive comment or remark. It's a comfortable balance; their kids are always self-sustaining. Retsu often preferred the quiet and still, offering to sit with Raion if only to have an excuse to get out of Hinako's constant insistence to play. Hinako would then bolt off to make friends with any other kid who would let her talk to them, never taking no for an answer—which in turn can cause Kazumi or Katsuki to have to step in and remind her about boundaries.

Hinako eventually bolts back over to the group, body slamming Kazumi where she's lounging, knocking the wind out of her as her hands brace directly into her mother's gut. "Mom! Can you come play with me? Please? You said that you'd play catch with me today!"

Kazumi wheezes, pushing herself upright and pushing Hinako off of her stomach. "Hin—I told you not to—do that—you aren't that little anymore—"

Hinako slides off of her stomach as she scrambles to her feet and starts bouncing on her heels. "Can we? You brought the ball, right? Does dad have it?" She immediately turns and zips over to Katsuki, who immediately braces a hand against her forehead with a growl.

"Ah-ah, apologize to your mother first."

Hinako blinks, peering around his arm to look up at him in genuine confusion. "For what?"

Katsuki rolls his eyes, pushing her back by the forehead to point at Kazumi, who is just catching her breath as Denki pats her shoulder in faux-sympathy. "For using her like a human trampoline. You gotta stop doing that sh—crap." His eyes dart to Aimi sitting nearby, who meets his gaze with a raised eyebrow before he clears his throat and shoves Hinako forward. "Apologize. Then I'll get your stupid ball."

Hinako lets out an exaggerated groan as she trods over to Kazumi. "Sorry, mom." She puts her hands on her hips. "I'll try to remember you don't want to me to be excited to hang out with you. My bad."

Denki immediately smothers his laughter behind his hand, turning his head away as he gives Kazumi another slap on the shoulder as she sighs, long-suffering. Katsuki immediately bristles. "That is not an actual apology and you know it, brat!"

"But I didn't even do anything!" Hinako whines, moving her hands from her hips to cross her arms. "I didn't even land that hard—"

"Sis."

Hinako jumps slightly at the soft sound of Retsu's voice. She glances towards her sibling who is staring at her with his usual impassive expression. Her tail lashes irritably. "What?"

"You knocked the wind out of mom," he replies smoothly. "You could've hurt her."

Hinako's face scrunches up. "She fights villains! She's not gonna get taken down by—"

"It's the principle of the thing you damn brat!" Katsuki barks, and Hinako jumps as she realizes her father has moved right behind her. "Doesn't matter if she fights villains, that's no excuse to go using her like your personal landing pad!"

Kazumi finally interrupts with a low snort, finally managing to catch her breath. "Alright, as charming as it is for you both to defend my honor, you don't have to dig into her that hard." She pushes herself upright, cutting off Katsuki's retort. "But. If you're going to use me as your personal landing pad, that means I get to use you as my personal weights."

Hinako blinks, stiffening. "Weights? What does that—AUGH—!" She's cut off as Kazumi scoops her up into her arms, easily lifting her above her head. Her protests quickly devolve into giggling squeals as Kazumi makes a show of bouncing her above her head.

Katsuki watches, exhaling slowly through his nose in exasperation as he watches Kazumi swing her around before dropping her onto her feet. He shakes his head as he digs out a softball from one of his pockets and tosses it to Kazumi. "You're gonna start enabling her bad habits, y'know that?"

Kazumi catches the ball with ease, rolling her eyes exaggeratedly as she tosses the ball into the air and catches it. "I like to think of it as positively reinforcing her not using me like a trampoline."

Hinako starts bouncing in circles around Kazumi, her tail whipping back and forth as she keeps her eyes fixed on the ball in Kazumi's hands, ignoring the conversation going on over her head. "We're playing catch, right? You said you wouldn't hold back since we're not at the house!"

Kazumi chuckles as she starts to walk away, still tossing the ball idly in one hand as the other moves to ruffle Hinako's unruly hair. "Yeah, yeah, kit, we're playing catch. C'mon, let's move to the field over here, yeah?"

As the pair move away, their words turning into a loud chatter, Katsuki watches them with his arms crossed before shifting his gaze down to Retsu. The boy has just turned his attention away from his sister and is adjusting how Raion is resting against his leg, his expression impassive as ever. Katsuki sighs heavily through his nose before scrubbing a hand down his face and moving to sit back onto the bench next to Aimi.

Denki rolls over onto his side, his gaze darting between the two groups before sitting up with a theatrically large stretch. He then hops to his feet, dusting grass off his pants before trotting over to Aimi, dropping his chin onto the top of her head. "Hey babe, wanna go grab some street snacks? Kacchan and mini-chan can keep an eye on our little guy for like, five minutes." He shoots Bakugo a grin, who responds with a low grunt as he leans back in the bench; as close to an affirmation as he can get without saying it outright.

Aimi glances briefly over to Raion one more time before nodding, pushing herself upright as she glances down the busy street. "You want the kebabs? Or the shaved ice?"

Denki moves around the bench, wrapping an arm around her shoulders as he guides her off towards the nearest street vendor. "Actually, I was thinking of this one place that has a special on.."

His words fade into the chatter of the park as they walk off, leaving Katsuki alone with the two youngest kids. He stares up at the sky, watching the clouds drift, occasionally glancing down to the pair. 'Keeping an eye' on the two might as well be asking him to keep an eye on a marimo. He watches the way Retsu watches the park, his expression always the same near-deadpan that would give their old homeroom teacher a run for his money. He has the same sharp glint in his eyes—showing that he isn't just existing but he's paying attention. Watching, listening, always attentive.

He can't help the slight smirk that crosses his face. He might not have the attitude that Hinako has, but Retsu is definitely his kid in that right.

Sighing, Katsuki leans further back in the bench and glances over to his wife and daughter. Kazumi is definitely holding back—if she used her full strength it probably would land on the other side of the prefecture—but she's definitely going harder than she usually does on the kid. Hinako is giving her all, throwing her entire body into every throw as Kazumi laughs and catches it with ease. She's giving out pointers with every throw, demonstrating a 'proper' throw with every toss, showing different techniques. Hinako pretends to not care, but he notices that with every returning throw she's shifting her stance slightly, throwing with different parts of her arms, and her tongue is peeking out with the mild focus she gets into when learning something new.

The back and forth of the ball, each toss rapidly increasing in velocity, is something that normally puts him on edge; but he trusts Kazumi to keep it from spiraling too far out of hand. He leans back once again on the bench, tilting his head back fully along the headrest as he closes his eyes.

It's a nice day out. The wind is gently tugging at his hair, chasing away the summer heat while the sun keeps his skin warm. The sounds of chatter and laughter with the occasional excited shriek from a child is relaxing in its own right—the sheer peace of it. No villains, no fighting, no societal collapse. Just an average weekend out with his and his friend's families. Another slow breath escapes him, his shoulders relaxing against the bench.

Then three things happen all at once.

Hinako's laughter cuts off sharply into a sharp, panicked yelp. Kazumi immediately lets out a half-screech half-yelp of, "*Hin—*Retsu—!"

And then an explosion nearby—strong enough that Katsuki had to hold an arm up to his face to protect from the whipping winds and grass that accompanied it. Without thinking twice he lunges off of the bench, already suspecting the worst—villain attack, quirk backfire from someone else gone wrong—he doesn't know, he had his eyes closed. Stupid. He's already lunging to protect Retsu and Raion, already hearing the latter's sharp cries of panic— only to freeze when he sees their positions.

Retsu is sitting with one hand raised, a stunned expression across his usually impassive face. His outstretched hand is trembling slightly, the other one gripping Raion as he wails and clings onto Retsu in turn. Somewhere across the street there's the sound of shattering glass followed by a round of surprised yelps, but Katsuki doesn't look that way yet.

Because his son's hand is smoking. Smoking in an all-too familiar way that he sees almost every day in hero work, that he's seen since his quirk manifested.

.. Since his quirk manifested.

The gears click just as Kazumi and Hinako both bolt over, the former in a similar state of shock, while the latter is bouncing on her heels with stars in her eyes. "Retsu! That was *so cool—*is that your quirk?! You got an explosion quirk like dad?! I'm so jealous—!"

As Katsuki and Kazumi share a bewildered look, Denki and Aimi come rushing back. "Hey—everything okay? We heard an explosion and something went flying across the street—!" Denki is already in full dad mode, immediately moving Raion. Aimi is close behind him, though a bit slower as she drops her purse and bag of fresh snacks onto the bench. They both pause as they process the scene. Hinako is still ranting, trotting around in circles around Retsu, who still haven't moved, still stunned with one hand outstretched.

Denki moves first, scooping Raion into his arms, who's still wailing. He immediately starts murmuring soft reassurances to him as Aimi quickly strides to his side. "What happened?" Her voice is sharp, her gaze flicking up to Katsuki. "Bakugo, you said that you wouldn't use your quirk near Raion—"

"Wasn't me, Glasses," Katsuki quickly snaps, the insinuation quickly snapping him out of stupor. "It was—!"

Hinako quickly interrupts, still bouncing in excitement. "Retsu got his Quirk! It's like dad's!"

Aimi quickly looks to Kazumi, who nods dumbly. "Yeah," she says in a dry voice, still rather shell-shocked that her five-year-old son just managed to create an explosion that Katsuki wasn't able to pull off until UA. "Uh.. Definitely an explosion quirk."

There's another beat of silence before Katsuki kneels down in front of Retsu, grabbing his wrist and inspecting it. He knows more than anyone the drawback of large explosions, and one that large without any training or support equipment had to have some sort of drawback. Sure enough, Retsu flinches as Katsuki grabs him, causing Katsuki to exhale sharply through his nose. "Thing has one hell of a kick," he mutters as rubs his thumb along the tendons. "You good?"

Retsu looks down to where his father is massaging the tender muscles of his wrist, flickers of pain dancing along his eyes. "Didn't mean to," is all he says. His voice is softer than normal, clearly shell-shocked, and his first reaction is—naturally, for him—apologetic.

Kazumi clears her throat, turning to look across the street, where the ball had flown and launched itself into the nearby pastry shop. "I'm going to.. Go make sure nobody got hurt. And apologize. And.. Pay for the damages," she says, each statement causing her to take quicker strides towards the gathering crowd across the street. She then glances over to Hinako, who's inching closer to Retsu with blatant curiosity, before sighing. "Hin, you're coming."

"What?! But I wanna—"

"Now, kit. C'mon."

Hinako whines dramatically but quickly bounces along, quick to direct her chatter towards Kazumi instead. Katsuki watches her go before exhaling sharply, looking up to Aimi. "Your brat okay?"

Denki nods, still gently bouncing Raion on his hip as he looks him over. "Yeah, he's good. Just spooked him—and everyone else in a mile radius." He looks over to Retsu, who is flexing his hands with a pinched expression. "What about you, mini-chan? You doing okay?"

Retsu nods faintly, breathing out slowly. "It.. I don't know what happened," he says quietly.

Denki offers a sheepish smile, handing Raion off to Aimi to sink down into the grass next to him. "Well, that's just how it goes with quirks sometimes. Mine shot off randomly in the middle of class, short-circuited my phone, and I was full whey-mode for an hour." He chuckles, leaning back on his hands. "My school called my parents and they all freaked out. Thought I'd had a stroke or a seizure or something until I came to and told them it was just my quirk."

Retsu stares down at his hands for a few moments, his fingers twitching. Katsuki watches, eyes narrowed, at how easily Denki seems to handle the situation. When Hinako got her quirk it was Kazumi who was there—bringing her to his agency with a puffed tail while the brat was a giggling, napalm-coated mess. He hadn't needed to comfort her or offer reassurance; she'd been excited and lobbing globs of her quirk all over his office.

Retsu, though.. He was staring down at where Katsuki was still idly rubbing his wrists like he'd just killed someone. He knows the kid is quiet by nature and he probably wasn't thrilled to have his father's quirk, but he didn't know exactly what to say. So he sighs through his nose and releases Retsu's wrist, giving him a light ruffle of his hair. "You'll be fine. We'll get you some wrist guards to make sure you don't hurt yourself if you accidentally set it off. Then we'll figure out how you use it and go from there."

Go from there is a loaded term, granted that Retsu has shown zero interest in becoming a hero compared to Hinako. He assumes that he'll want to learn the activation to avoid it, if anything, but he'd be lying if some deeper part of him hoped that he'd open up to the idea.

For now, though, Retsu just nods; flexing his wrists again before turning to look up at Denki. "I'm sorry for scaring Raion," he says, his gaze turning towards Aimi. "I hope he.. Isn't afraid of me."

Denki chuckles, nudging Retsu with an elbow. "Nah, he's just a baby. Probably doesn't even recognize that the big scary noise came from you at all."

Aimi nods in affirmation, shifting to carefully kneel on the grass next to Denki. "I'd actually guess he thought you protected him, if anything," she says softly. "You probably made him feel safe in the moment."

Retsu looks to Raion, his brows pinching further. "But he was crying.. And immediately let go of me.."

Denki snorts. "That's because it was his dad picking him up, Retsu. You know he loves me—" he snorts as Aimi elbows him lightly, "—us. His parents. Of course he's gonna pass up you for us, that's just Baby-101."

Retsu falls silent again before sighing softly, looking down at his hands again. "Okay," he murmurs.

Katsuki raises an eyebrow, but he knows that's about as much of an assent that Retsu will give in the moment. He sighs as he hauls himself to his feet, dusting grass off of his pants. "C'mon, brat. Let's go get something."

Retsu looks up before slowly rising to his feet. "Something?"

Katsuki grunts in affirmation. "Your choice. There's a million and one vendors right now, we'll get whatever you like." He pauses as he notices Retsu continue to look at him, a bit perplexed, before rolling his eyes. "You got your damn quirk, you think I'm not going to celebrate that you got mine?"

Denki audibly snorts, muttering something that sounds faintly like a sing-song "ego", but Katsuki ignores him. He ruffles Retsu's hair again for good measure before gently pushing him forward by the shoulders. "Now. Or I'm gonna pick, and I know you hate ikayaki the way I like it."

That speeds Retsu up, and he quickly starts towards the street vendors with a bit more speed. "Does a drink count as something?"

"Depends. You gonna just ask for some juice so you don't have to actually pick something?"

"No."

"Hah. Yeah right, try again, brat."

".. Taiyaki."

"That's more like it."

Katsuki watches Retsu walk ahead, something tight and unfamiliar settling in his chest. Not fear—he knows fear. Not worry, not really. This is pride. True, real pride. It sits heavier than he expects.

Retsu doesn’t look back, already scanning the vendors, moving forward like nothing’s changed—but everything has. Katsuki knows it. Kazumi knows it. Hell, the whole damn street probably knows it after that blast.

His kid. His quirk.

Katsuki scoffs under his breath, shoving his hands into his pockets as he starts after him.