Requested by GoKotoha
Thank you dearly for writing those requests for me! I hope you like this oneshot. It’s a special one and I’ll explain why.

Alright, I was going through old oneshots I’ve made in the past from when I wrote for One Piece and fell in love again with one of them. It was called Dog Days: Law x Reader. I really wanted to put a new spin on said oneshot and modernize it into the MHA world as well as with my current writing style. I’m not entirely sure why I treasure the oneshot so much, it just has that special place in my heart.

With each new generation comes monstrous quirk genetic mutations. The merging of two quirked parents, be it useless harmless quirks or that of in between, can bring upon the most destructive of quirks making each generation more fearful and powerful than the last.

While in most cases the quirks of each parent mutate to make a new one upon their child’s birth, it wasn’t uncommon for a child to take on only one of their parent’s quirks. (Y/n) (L/n) was in that exact position and thankful for so. Her mother, as Pro who’s nicknamed the Angel, as she harnessed the power to steal a light source and use it however the user sees fit. (Y/n)’s father on the other hand was also a pro hero who earned his wive’s heart through hard work and dedication. It was like Beauty and the Beast as he was rightfully nicknamed the ‘Beastman’ for his ‘wolfish’ appearance that’s always changing by the day. With great big claws and strength, this quirk couldn’t be more perfect for combat. However, as most quirks do, the ‘Beastman’s’ quirk had a slew of downsides. How a mutation quirk can never be turned off would easily explain how he’s forever stuck being abnormally hairy, bearing fangs, sharp claws, pointed ears and bushy tails. That’s why (Y/n) was lucky to have been gifted with only one of her parent’s quirks and not the other.

Or, that’s what she thought until her sixteenth birthday came and went.

From being apprehended to being thrown into her room at UA for surveillance and the safety of others, (Y/n) could only be viewed as a monster.

Once Shoto Todoroki heard the news of his beloved’s uproar, her new bodily appearance and behavior had caught his attention. ‘She like a wild animal!’ they all claimed. ‘Must be the work of villains. Who would do that to a teenager?’ But Shoto knew all too well that this wasn’t the work of villains but genetics itself.

A few phone calls were made.

“Is it possible that (Y/n) awakened your half of the quirk?”

“She did just turn sixteen,” (Y/n)’s father replied in his lispy voice given the great size of his canine teeth. “This is the age when you kids are mentally and hormonally matured not to forget that… Um… You kids legally can do the dirty now. It only makes sense that her wolf instincts have awakened. Sixteen for me for a rough time as well.”

Shoto wore a sour face, “So you’re telling me she’s in heat?”

“Well when you put it like that,” the Beastman awkwardly scratched at the back of his neck.

“I’m not having sex with your daughter…” Shoto groaned. As much as he’d like to, that’s more of a thing he’d do a couple of years down the line when she has a ring around her finger.

A growl ripped across the phone line, “Have sex with her and I’ll rip your balls right off!!!” The Beastman quite literally barked.

“I don’t think she’s in heat anyways,” Shoto sighed as he brushed off that threat with ease. He has Katsuki Bakugou to thank for such. “I think it’s just the quirk talking. (Y/n)’s apparently attacking everything that moves. How am I supposed to help her calm down?” (Y/n)’s reverted to the mental state of a wolf and that’s that. Wolves fight, hunt and act recklessly around humans. Everything she’s sadly going through.

“Well…” The Beastman took a breather as everything Shoto had to say put him at ease. Asking your daughter’s boyfriend to have sex with her? Not in a million years!!! “Whenever I get too angry, all I see is red. Only when my close friends and family stare me right in the eye and tell me everything’s gonna be okay is when my mind will clear. Do that, and (Y/n) should be fine.”

“I’ll do that then,” Shoto bowed his head. “Your daughter will be okay. I promise.”

“Much appreciated Shoto.”

The call was brought to an end and thus Shoto knew what he had to do.

He ran to UA and right to the class dormitory where his girlfriend was being detained. It took a lot of persuasion, but Mr. Aizawa heard Shoto out and allowed him within (Y/n)’s dwelling. Apparently, Mr. Aizawa’s quirk was useless against (Y/n) since all of her problems were trapped within her mental state unlike Tokoyami where a simple activation of his quirk could quell Dark Shadow’s rampage. Now everyone is being cautious, and multiple students were on standby to help Shoto if there’s ever a call to help.

“(Y/n)?” Shoto knocked on the door with one hand. The doorknob tightly clenched within the other. No answer and not a sound to penetrate his ears from the other side. He proceeded to open the door completely as the action flooded the room with the hallway’s light despite how the lightswitch was in the on position. (Y/n) must’ve stolen the lightbulb’s power no doubt. Shoto would’ve thought (Y/n)’s mind was too ‘animalistic’ to even think to use her other quirk.

Shoto allowed his eyes to adjust to the dark lighting as Mr. Aizawa closed the door behind him. He made a careful way to the windows and clenched the silky curtains within a balled fist. No sound. He would’ve thought (Y/n) would move or attack him by now. Maybe even a sound would suffice. So, Shoto pulled the curtains open ever so slightly as the room was illuminated once more and there she was. Shoto didn’t expect what his eyes locked upon. “What the hell are you doing?” Shoto snapped as he lurched at the being that sat hunched over upon the floor. That being was (Y/n) who had succumbed to a feral nature as she scratched desperately at her head with her frighteningly long claws. “(Y/n)!” Shoto snapped once more as he snatched the girl’s wrist. (Y/n) stopped her actions. Her head snapped into Shoto’s direction. He was petrified at the sight of her hair so drenched in blood that it dribbled upon the floor, and what was once pointed canine ears scratched up to oblivion.

(Y/n) allowed a deep growl to vibrate from her chest as she bared her fangs at Shoto. It was like her strength was multiplied times ten as she effortlessly threw Shoto off from her and into the ground. She was rearing back, about to sink her teeth into Shoto’s throat. He threw his arm up in time to shield himself as she latched onto his arm with the crushing strength of her jaw. “(Y/n)!” Shoto hissed in pain. “Hear me out! Everything will be okay!” He shouts yet (Y/n) didn’t flinch. With his free hand, Shoto snatched a handful of her hair and used all of the strength he could muster in order to force her to look him in the eye. “Calm down! It’s me!” Those words earned a growl from the beast. “Snap out of it,” the pain was finally catching up to him and his strength was fleeting.

Yet, it was Shoto’s pained response that began to clear the haze for (Y/n). She finally could see Shoto’s face and not a big blob of matter and he was covered in his own blood. (Y/n) unlocked her jaw, her mouth flooded with the coppery taste of crimson and finally took the deep breaths she needed. “Shoto…” (Y/n) found difficulty speaking with her new fangs. Every s came out as a lisp. “Shoto… I’m so sorry…”

“It’s okay,” Shoto breathed as he pressed a hand to the back of (Y/n)’s head and pressed it down until she laid it upon his chest as it was the best embrace that he could offer. He wanted her to know that everything was okay.

A moment later, after (Y/n) could finally calm down and see everything for what it was, she tried to retrieve help for Shoto but was declined given her previous actions. Shoto managed to pull himself together and leave the room. (Y/n) was weeping silent tears till he came back with bandages of his own and a heavily padded arm. “What made you think ripping off your ears would solve anything?” Shoto sighed as he snapped his fingers and pointed at his feet. Yes, he won't deny that he's treating his girlfriend like a dog. considering everything that’s happened and how she’s quite literally part dog now, (Y/n) expected Shoto’s behavior.

(Y/n) ignored Shoto and instead felt the weight of the pain her new canine ears endured. During that crazed fit, (Y/n) couldn’t pinpoint any reasons behind her malicious act of ear destruction. Shoto snapped his fingers again that echoed within the tiny room. Shoto wanted his way and she couldn’t deny him. So she crawled over with a pained groan and sat at his feet. Not because she wanted to, but because she was indebted to him after this whole incident. The hairs on (Y/n)’s bushy tail stood on end, and what was left of her canine ears were folded downwards.

“I didn't even realize I hurt myself so badly until you drew me out of the fog,” (Y/n) sighed. 

Shoto knelt down beside her. He angled her head up to meet his gaze. “Well I am your boyfriend after all…” Shoto hummed, examining her canine ears to the best of his ability. Can you really even call them ears anymore? He took a seat in the chair behind himself and carefully used his icy half to numb the wounds she’s inflicted upon herself. (Y/n) began letting off an animalistic growl alongside the pain. Ignoring it all, Shoto went to work despite this being a doctor’s job. He began by cleaning up her wounds and gently bandaging the base of the ears where (Y/n) previously scratched at mindlessly.

“There,” Shoto ruffled her hair.

“Quit treating me like a dog,” (Y/n) began to pout. Although, she really couldn’t stay mad at him. Shoto’s only being himself, the man who’s come to love her for herself. “Forget what I just said… I guess I am my dad’s daughter after all…” The tail, the ears, the teeth? It all came from The Beastman’s genetics. And here she was being thankful for years on end that she got the easy way out.

“You'll be fine (Y/n)... Don’t pout,” Shoto smiled softly. It was a sight that was a rarity to behold. He began to pet her on the head once again.

“So you don't mind having a werewolf girlfriend?” She grinned pushing up on Shoto’s hand as for some reason in the back of her mind she was loving all the attention he could give.

“As long as you don't try to kill me again, I think we'll be just fine.”