Author's Note: For people wanting to know why I'm writing All Might / All for One, it's because the Wyrm team in the Vault Olympics requested this fic as their winning prize. Credit (blame?) goes to B_O_M_B for this prompt. I'm charging Goofy_Boss with fic child support for brainstorming with me. (I'm forbidden to mention Gentrychild's contribution to the ship from hell thanks to a certain notorious court case. This is me loudly not mentioning it.) At least this still isn't as cursed as my All for One / Endeavor fic.

Toshinori Yagi loved Izuku Midoriya like his own son. The boy was the perfect aspiring hero, from his kindness to his courage to his absolutely feral ferocity. Toshinori had first started walking Izuku home from school in order to have more time to discuss their lessons. Inko had invited Toshinori in for dinner. From there, it had become a regular occurrence. Toshinori had a deep admiration for Inko Midoriya. She was a sweet, genuine soul. After her divorce, she'd taken over primary custody of her son while her husband worked abroad. Clearly her love and generosity had helped Izuku grow into an amazing person. It was a delight to be part of their lives.

Then Hisashi Midoriya had come home from America, and Toshinori had been awe-struck at first sight.

Hisashi was a giant of a man, the first person Toshinori had ever met taller than himself. Muscles rippled over his body. Intelligence and charisma glinted in his ruby eyes. His curly white hair looked so soft, Toshinori had to consciously hold himself back from ruffling it. Hisashi had the most beautiful curls and best hair of anyone Toshinori had ever seen.

Apparently Inko was on very good terms with her ex-husband, because she'd invited him to stay for dinner too. Toshinori had made an effort to close his jaw and offer a handshake. Hisashi had been polite but distant. His coolness had only raised him in Toshinori's estimation. Naturally, Toshinori got sick and tired of everyone fanboying over All Might. Hisashi seemed so genuine, not intimidated by celebrity.

Over dinner, Hisashi had spoken persuasively about the flaws in hero society and the corruption in the HPSC. In that moment, Toshinori had fallen head over heels in love. A hot body was a plus, but nothing compared to a brilliant mind sharing all of Toshinori's own criticisms of the HPSC. It had been a pleasure watching Hisashi rip those morons apart.

Yet Toshinori knew it would be a bad idea to get involved with his successor's father. He didn't have time to date either. His busy career had ruined every other romance in his entire life. If Toshinori asked Hisashi out on a date and got rejected, or if it didn't work out in the long run, then it would make family dinners unbearably awkward. Toshinori didn't want to lose the most important connections in his life. Even if Hisashi reciprocated his feelings, how would Izuku react? Toshinori couldn't bear to upset his boy. So he resigned himself to pine in silence, and occasionally sneak peaks at Hisashi's absolutely amazing bod.

Izuku had noticed All Might had it bad for his dad. How could he not notice? All Might was never rude or avert, but he got a dreamy look in his eyes whenever Hisashi started monologuing. Most people couldn't stand Dad's long speeches. Either they'd get angry or their eyes would glaze over. This was a clear sign Hisashi had met his soul mate.

Of course Izuku fully supported obtaining All Might as a stepdad. Not only would Izuku finally be able to collect the real All Might, he'd also become the heir to All Might Merch Industries. Basically Izuku hadn't been so determined to make something happen since he'd decided to become a hero. And his idiot dad had better not screw it up for him.

During one of their regular lunches at school, Izuku told All Might, "You should ask my dad out."

All Might choked on a rice ball. After guzzling water, he said, "Young Midoriya, I don't know what you're talking about."

"You should call me Izuku, since you're going to be part of the family." Izuku grinned. "Dad likes you, too."

"He does?" All Might demanded, agog.

Actually, Izuku hadn't picked up on any such sentiment. Hisashi seemed a bit aloof and competitive around All Might. Possibly his son having another father figure had made him defensive. But Izuku didn't care. His often absentee father now had the perfect chance to make up every single missed birthday party and sports festival to Izuku. All Hisashi had to do was bang All Might. As All Might's entire fan club would no doubt insist, it wasn't an onerous ask. Izuku felt certain his dad would not be able to turn down All Might's general magnificence if given the opportunity.

So Izuku lied through his teeth: "Yeah, Dad's shy so he's been waiting for you to ask him out."

"Oh." All Might turned deep scarlet. "Are you certain you wouldn't mind?"

"I'd be thrilled to see you both happy." And to see my merch collection become the largest in the world. Suck it, Sir Nighteye.

"Your mother…"

"Mom and Dad have been divorced for a long time. She'd want Dad to be happy too."

All Might looked away. "I can't guarantee that things would work out between us. I don't want to make everything awkward if we don't suit."

"That would never happen. Even if you two broke up, we'd all handle it like reasonable adults, and you'd continue to be welcome at family dinners." Because otherwise Izuku would ritually sacrifice his father and bury the pieces around Japan. He smiled brightly. "I really think you should give it a try. I'd support you completely. My dad likes Italian food."

All Might swept Izuku up into a grateful hug.

Hisashi had been very nervous when the blond buffoon first showed up at his ex-wife and son's home. He kept a very strict work-life separation. When acting as All for One, he'd always worn a helmet with a voice modifier. After his son had been born, Hisashi had decreased villain activity to spend more time with his family. He'd given up on many evil schemes, including his plan to destroy the Shimura family. He'd cut his work to the minimum he could get away with and retain control of the underworld. It still hadn't saved his marriage. Despite his wife constantly complaining about him being away, it turned out she liked him even less when she saw him frequently. At least as a result, Hisashi had avoided any major confrontations with All Might. The hero had only ever seen him from a distance and from behind. There had been no recognition in those blue eyes.

After learning his son had somehow obtained Yoichi's quirk and entered hero school, Hisashi had rushed straight home. But he'd been too late. Izuku had already gotten attached to U.A. and all his silly little friends. All Might had entrenched himself into the family, having the nerve to intrude on family dinners and steal Izuku away for constant training. Hisashi had tried to drive off the blond buffoon with his scathing critiques of heroes, but the idiot actually seemed to agree with what he said. Was it real or pretend agreement to drive him crazy? Alas Hisashi was prohibited from criticizing the number one stupidest hero directly to his face because Izuku did not tolerate All Might slander in his house. (Actually Izuku was willing to listen to any discussion backed up by solid evidence. But All Might had this regrettable tendency to actually learn from constructive criticism and even thank Hisashi for it.)

Oh, if not for the need to preserve his civilian identity, Hisashi would have already given All Might his opinion on heroes with his fist.

Washing dishes after dinner, Hisashi became lost in his murderous fantasies. He did not notice All Might coming up behind him until the hero cleared his throat. Hisashi startled, nearly activating a quirk that would have electrocuted his sink. He dropped the plate.

"Whoa!" All Might lunged forward and caught the plate before it hit the ground. "Sorry for startling you."

"It's fine," Hisashi said between clenched teeth, hoping to make the buffoon leave faster.

All Might shuffled his feet and stammered, "M-may I have a moment of your time?"

"You already are," Hisashi pointed out. Since meeting All Might in a civilian setting, he'd been shocked at how often the hero blushed, stammered, and tripped over his words. Perhaps All Might's public mask differed from his private face. He was a bit less annoying without all the loud catchphrases…a bit.

"I'd like to take you out to dinner," All Might blurted out, his head lowered and his cheeks crimson. "On a date. Just so there are no soap opera misunderstandings. Of course, if you're not interested in me that way, then I'd be happy to go as friends…"

stopped working. All Might? His mortal enemy and heir to a legacy of heroes that existed to destroy him? WAS ASKING HIM ON A DATE?! This had to be a trick or a trap. Perhaps All Might wanted to lure him away from this civilian neighborhood to arrest him.

But it didn't seem like All Might had enough acting ability to pull off a full-body blush. Hisashi was very handsome and charming, so people fell in love with him all the time. This posed an opportunity. Hisashi could use this to obtain hero secrets, or lure All Might to his death, or find a way to obtain One for All, or maybe even just break All Might's heart so badly he no longer intruded on family dinners.

Hisashi tilted his head. "Only if you take me to eat Italian."

All Might replied, "I've already made a reservation at Aroma."

The most prestigious Italian restaurant in Musutafu? Perhaps this evening wouldn't be a total waste.

Peeking from the doorway, Izuku pumped a fist in victory.

Hisashi had been prepared to be difficult and find fault from the moment All Might rang the doorbell of the fake apartment he only maintained for appearances. Yet All Might greeted him with a giant bouquet of at least a hundred roses. "For you," he said with a flourish.

Caught off-guard and secretly a little impressed, Hisashi only said, "Adequate."

"Do you prefer different gifts?" All Might asked anxiously.

Hisashi shrugged as he divided the flowers between a couple vases. "I prefer insubstantial gifts." By this he meant One for All, the only thing of any value the blond buffoon had to offer.

All Might's eyes lit up. "Oh, how romantic." Hisashi wondered what the idiot had misunderstood this time.

At least the fool had the common sense to reserve them a private room in the upper story of the restaurant. Otherwise his fame would have been a constant interruption. Even so, Hisashi could detect two spies in the building: a villain from an organized crime faction in the neighboring room with eavesdropping equipment, and an HPSC agent with a disguise quirk infiltrating the wait staff. Ugh, what a pain to date a celebrity. They must have All Might under tight surveillance to have noticed the date so quickly. This was why villains were much smarter to remain in the shadows.

As the fake waiter brought their water, All Might said, "Please tell me about yourself."

Hisashi normally wouldn't turn down that request, but if he told All Might the real story about his life, it might be used in court against him. Thus Hisashi decided to turn to his distant childhood instead, which no one knew enough about to connect back to him. "I'm the oldest child of my family—"

By the time Hisashi had finished his story, All Might was sobbing into his handkerchief. "You had such a rough childhood. You were an amazing big brother!"

"I was," Hisashi agreed. He'd always known that everyone would say the same if he just told his side of the story instead of Yoichi's deeply biased one.

In a serious voice, All Might said, "I'm sorry for the loss of your brother. And your parents too, even though they mistreated you. I understand how it can be hard to lose even family you have a bad relationship with. My own parents threw me out as a preteen for being quirkless."

"That's just disgraceful," Hisashi said. "Family should never turn on each other." He meant it—even the blond buffoon shouldn't have been treated like that. Maybe All Might's bad childhood explained how poorly he'd turned out.

Although, All Might hadn't seemed quite so bad during their date. He'd dropped all the cheesy catchphrases and the exaggerated smile in favor of a softer, genuine smile. This man was vastly preferrable to the TV persona.

Whatever moment they'd been having was interrupted by the fake waiter. "May I take your order?"

While giving his order, Hisashi contemplated poisoning All Might. Would it be a bit too obvious, though? He'd certainly be a suspect as a fellow diner. Hmm, maybe the trick would be to make it look like an accident. "I have to go to the bathroom," Hisashi said, standing up.

Using an invisibility quirk, Hisashi slipped into the kitchen and swapped All Might's meal with the yakuza next door. That was stage one.

When the meals arrived, All Might sighed and looked down at his plate. "Oh dear, they got my order wrong. This has ginger and I'm allergic."

Hisashi said, "You can have half of my meal." He planned to poison his own food (he was immune) to make himself look like the innocent target. That was stage two.

All Might said, "I couldn't possibly."

Summoning all the steel in his spine and the murderousness of a century, Hisashi batted his eyes. "Oh, I insist."

Next door, the yakuza started choking. Apparently the idiot had poisoned All Might's meal—and bitten into the swapped dish without looking. The yakuza sure did know how to hire fools.

All Might shot to his feet in a flash. "Excuse me, I heard someone in trouble."

While All Might gave the yakuza CPR, Hisashi texted on his phone to take credit for the hit as All for One. The yakuza in question had killed several of his own messengers, so it would improve morale to be seen to retaliate. The genius ruler of the underworld could turn every obstacle to his advantage.

Alas, the original murder plan had been a wash. By the time All Might finished saving his life and the yakuza was taken away in an ambulance, the food had gotten cold. The restaurant brought them two new dishes in gratitude for preventing a death under their roof.

Sitting back down, All Might twisted his hands. "I'm very sorry for abandoning you."

"It's fine," Hisashi said, putting away his phone. He'd had his own business to take care of, so it had actually been quite convenient.

All Might bit his lip. "I've had problems running off in the middle of dates before. My lifestyle makes it hard to have a romantic night out."

"Really, I don't care," Hisashi said bluntly, referring to how he didn't care to hear about All Might's problems.

All Might's eyes misted over. "You're such a good person."

"Uh-huh." Hisashi never turned down compliments even if he preferred to be called evil. "Why don't you tell me more about your work?" This would be a great chance to spy. Belatedly, Hisashi remembered to add, "I'm sure it's fascinating. I'd love to hear about the nitty-gritty details, not just the big events." Because he wanted to learn insider information he couldn't get from reading the news.

All Might sat up straighter. "How wonderful! Normally everyone just wants to hear about the heroics, not listen to me bitch about paperwork."

While All Might started talking, Hisashi noticed the fake waiter drifting closer. This was completely unacceptable. Hisashi had gone to the great bother of dating his archnemesis to obtain juicy information for himself, not for the HPSC. How dare they piggy-back on his spying?

"Excuse me." Hisashi slammed his hand down on the table. He stood up, walked out of the room, and pushed the spy against the wall. "Give me that." He wrenched out the hidden wire and recording microphone from under the waiter's shirt, then crushed it between his fingers.

"I was just—" the waiter squealed, preparing an excuse.

Hisashi interrupted, "You were just spying on us for the Hero Public Safety Commission. Yes, I'm sure they flattered you about how they needed your disguise ability to help them keep Japan safe, blah-blah. You want to know the cold hard reality? The HPSC isn't interested in saving Japan, just keeping their own power and keeping people under their thumbs. They sent you to spy on Golden Boy over there because they can't control him." Hisashi jerked his thumb at All Might, who was watching from the table with his jaw hanging open. "You think Mister Perfect Hero ever broke a rule in his boring life? Nah, the HPSC sent you after All Might because they don't have any blackmail material on him, and that scares them. And if you got caught, they planned to disown you and pretend they never hired you. You're a pathetic dupe." Hisashi dropped the spy to the ground.

The fake waiter whispered, "I need to go rethink my entire life and career," then staggered off.

Hisashi called after him, "Before you quit, I'd like the chocolate mousse for dessert."

Behind him, All Might picked his jaw up off the floor and chuckled. "Hisashi, you're amazing! I've been dealing with HPSC spies following me around for decades. Many times before, I've tried to redeem them. It always took me months if not years because of the HPSC brainwashing. Yet you just cut through it in one speech! Seriously, you're cool."

Hisashi blinked in confusion. All Might looked at him with starry eyes as if he'd saved the hero's day. Weird, Hisashi had just been trying to provoke more trouble between the HPSC and All Might, as well as giving that fool a deserved tongue-lashing. How had he accidentally made All Might fall even more in love with him? Whelp, it couldn't be helped—someone as awesome as Hisashi just had that natural "it" factor.

Apparently the fake waiter had stuck around long enough to put in the dessert order, because another waiter came with the chocolate mousse after they'd wrapped up their main courses. Hisashi had taken careful mental notes on everything in the conversation related to hero business. Without much more spy business, he asked, "How is Izuku's training going?"

All Might snapped to attention. "He's the most talented student I've ever seen. Definitely the most talented kid in his class, though I wouldn't say that outside this room. I'm really impressed by his notetaking abilities. I only need to tell him something once for him to remember it."

"Why, yes, I taught him my notetaking techniques," Hisashi said, pleased.

"He's incredibly brave."

"Sometimes a little too brave," Hisashi sighed.

"Yes, I know how you feel. It troubles me when he rushes into danger, even though I'm proud of him. I know he has a knack for pulling himself out of the trickiest situations, though, just like he gets into them." All Might smiled. "He's a natural at making plans. And his quirk analysis deeply impresses me. I swear he's figuring out how to use my ability in ways I haven't after decades."

"My Izuku is brilliant," Hisashi agreed. "He has a natural knack with quirks."

"He's the best boy in the world."

"The universe, really." Hisashi decided that maybe he wouldn't poison his dessert and offer All Might a bite, after all. It was too nice to meet someone who properly appreciated his son. He could always kill the blond buffoon tomorrow.

All Might insisted on paying for dinner. Hisashi never turned down a chance to use someone else; however, in the end the restaurant comped their meal to make up for the near-death next door.

After walking Hisashi home, All Might paused at the doorway. "Thank you for giving me a chance. Would you like to go on another date next weekend?"

"I was already thinking the same," Hisashi said, since he'd failed to kill All Might this time.

"Thank goodness!" All Might clutched his chest over his heart. "This is the first time I've felt like I'm dating someone who likes me for me, not just All Might."

"Oh, I definitely don't like All Might," Hisashi said reflexively.

"I'm glad." All Might beamed. "That's really so wonderful of you to say."

"I'm great like that," Hisashi agreed, a little confused.

"I enjoyed myself a lot tonight," All Might said before leaving with one last smile.

Strangely, Hisashi had enjoyed himself, too. Wasn't that just confusing?

Toshinori practically skipped home, on the high from a fabulous first date. Hisashi had been so kind! He'd been interested in Toshinori as a person, including asking about his daily life, not just the flashy hero deeds. It had been great to meet someone understanding about the date getting interrupted by saving a life. For most people, the constant need to leave for work got old real fast.

The moment when Hisashi had verbally eviscerated the HPSC spy had been amazing. Toshinori had been stalked by spies ever since his hero career had taken off. The HPSC had also sent dozens of agents to seduce him. They kept sending people creepily younger than him. Toshinori tried to help those agents, who'd often been recruited as children. After he'd kept convincing their seducers to quit the business and get therapy, the HPSC had given up on that angle. But they'd continued to send people to spy on him. Toshinori had gotten to the point where he just ignored them and watched what he said. He'd noticed the spy, but not bothered to do anything, not wanting to interrupt his date a second time. It had been wonderful to see someone stand up for him and send the spy packing.

Toshinori also found it cute how Hisashi was a bit shy and withdrawn during conversation, but not afraid to stand up for what he thought was right. Nor was he shy about praising his son. Toshinori really appreciated what a great father Hisashi was. His love for his son had drawn in Toshinori from the beginning.

Also, Toshinori was glad Hisashi hadn't tried to sleep with him on the first date. Not that there was anything wrong with that. But Toshinori personally didn't feel attraction for people until he'd developed deeper feelings for them. Most of his dates tended to push him for sex after the first dinner, as if they just wanted to brag about sleeping with a celebrity. To say nothing of all the creepy quirk marriage offers and attempted baby traps. The fans who tried to date him were always tiring at best and creepy at worst. He just wanted to meet someone who wanted him for him, not All Might. Someone like Hisashi, who'd been genuine and a perfect gentleman on their date.

Touching his racing heart, Toshinori realized he'd gotten very close to developing serious feelings already. Which meant he ought to talk to Inko.

Inko shrugged. "Sure, I don't mind if you date my ex-husband. Though I can't say I'd recommend him."

"You two got divorced, after all," Toshinori said. "I'm sure it wasn't a pleasant experience."

Inko sighed and pushed back a lock of her hair. "Hisashi promises a lot of great things, but he doesn't always take responsibility. I'm not sure he even understands the concept that what's good for him might not be the best for everyone else." Bitterness colored her voice. "He'll stay out late without telling you when he'll return home. Date nights will get canceled at least half the time. And he'll never make it to your birthday because work emergencies always come up."

Toshinori chuckled. "I haven't celebrated my own birthday in years because of work. He sounds perfect for me."

"If he's what you want, then I give you my blessing." Inko kissed his cheek. "I hope it works out for you." In a softer voice, she muttered, "Because I'm not taking Hisashi back if it doesn't."

The next weekend, All Might showed up with a bouquet of bat orchids and said, "Since you prefer insubstantial gifts, I made a donation to a quirkless advocacy group in your name. I also brought you flowers, because you deserve those too. I noticed your favorite color is black. I hope you like black flowers."

Whoa, what a creative misinterpretation of Hisashi's words last time. Yet, reluctantly, Hisashi had to admit the bat orchids were beautiful. And it was a little flattering the blond buffoon had noticed his favorite color. Even his minions weren't usually so attentive.

All Might took Hisashi on a boat ride around the park. Noticing the children playing ball on the bank got them both talking about how Izuku was clearly the best child ever, far superior to the rest. Hisashi had been planning to shove All Might over the side of the boat, but he got too invested in the praise fest. He could always kill All Might next time.

On their next date, they went to the Kabuki opera. All Might proved able to carry on a surprisingly intelligent conversation about ancient Japanese plays and how Izuku was clearly such a genius they would need a new IQ scale to measure his intelligence. Hisashi had been planning to electrocute his enemy and frame the opera house, but he called it off because he wanted to hear All Might finish. He could always kill All Might next time.

Next, they climbed Mount Fuji. The lovely moment overlooking the cliff with a beautiful sunset in the background would have been the perfect moment to shove All Might over. But then they got into an exciting discussion about which was cuter, Izuku or the squirrels in the trees. Then Hisashi couldn't possibly murder All Might until they'd gotten done agreeing that Izuku was far more adorable than every single last bit of wildlife on the mountain. He could always kill All Might next time.

When work interfered with their next date, All Might made up for it by taking Hisashi to a black tie dinner with the most wealthy and powerful people in Japan. Hisashi stole so many of their quirks that he forgot all about killing All Might. They both agreed how superior Izuku was to the spoiled children present. Hisashi did subtly send All Might after a couple of his business rivals, getting rid of those half-rate criminals quite efficiently. It had been a useful evening.

Hisashi was the one to suggest the next date: an anime convention where there would be a panel on dawn of the age of quirks cartoons and a showing of the first Captain Hero movie. Although Hisashi hadn't followed most anime in years, he could not resist a chance to brush off his Demon King cosplay. All Might proved an astonishingly good sport, volunteering to dress up as Captain Hero even though he'd never seen the show. They attended the movie showing with many people taking excited picture of them. And All Might loved the Captain Hero movie! He offered thoughtful analysis and fresh enthusiasm on the strong points! Hisashi couldn't possibly kill Toshinori after that.

…Wait, when had All Might become Toshinori?

Hisashi paced the confines of his apartment, muttering to himself. Despite his usual armor of denial, he knew that it was odd he'd been spending so much time dating his worst enemy. Sure, he'd gotten some quirks out of it, but that didn't explain how much of his valuable energy he'd poured into meaningless socialization.

Izuku looked up from where he sat on the living room couch doing his homework. "Dad, would you like to watch my training with All Might tomorrow? I'd love to show you my new moves! Please, it would mean a lot to me."

It was no good trying those wide, innocent eyes on Hisashi. He'd used the same expression to manipulate people himself when he'd been younger and cuter. Hisashi arched an eyebrow. "Ducky, are you trying to parent trap your old man?"

"Is it working?" Izuku shrugged. "Look, Dad, if you marry All Might, then I inherit his merch empire. I would love you forever if you'd pretty please do your best to make this relationship work. Besides, is it any hardship to date Japan's most eligible bachelor?"

Hisashi hesitated. His knee-jerk reaction would have been that of course it was a hardship to date All Might. But the dates hadn't been hard at all. They'd been fun. "Hmm. Give me a moment."

Going into his office, Hisashi made a pros and cons list for dating Toshinori Yagi.

Pros:

1. Extremely rich

2. Dotes on me and gives me presents

3. Adores Izuku almost as much as Izuku deserves

4. Fits in great with the existing family dynamic, including getting along with my ex-wife

5. Access to confidential information and people with cool quirks

6. More than willing to be used to destroy the HPSC and other villains

7. A wonderful listener

8. Flatters me

9. Very generous and giving, easily bends to make the people he loves happy

10. If he ever finds out my real identity, I can throw it in his face and pretend this was all a clever plan

11. Great body

12. Having sex with him might result in me obtaining One for All (relatively unlikely after he passed along his quirk, but I've tried more ridiculous plans)

13. Banging Yoichi's successor would make my brother spin in his grave like a top and finally avenge my pain for when he ran off with a pair of thieves (this should actually be reason number one)

Cons:

1. Being All Might

The only con on the list belonged to All Might. There was not a single con to dating Toshinori Yagi. Well, Hisashi had never been one to deny himself anything he wanted.

Going back outside, Hisashi said, "I would be happy to attend your training…and accept your help in the related matter."

Izuku grinned in a manner as villainous as his father. "I'll provide my extensive fanboy knowledge to help you pretend to be charming."

Hisashi figured he should at least see if he could steal One for All before Toshinori completely lost the last embers, which meant a DNA transfer. Using Izuku's fanboy database, Hisashi had prepared his apartment with All Might's favorite flower (sunflowers) and made his favorite meal (bacon cheeseburgers). Izuku would be furious if he knew his knowledge was being used in the service of stealing his quirk. But: 1. It probably wouldn't work; and 2. If it did work, Izuku would never find out. Hisashi had learned from his brother not to let anyone he cared about discover his true profession. That list now included both Izuku and Toshinori. He'd pass off One for All's disappearance as the power fading over time and find a new quirk for his son.

But from the moment Toshinori slumped in, Hisashi knew this date would be interrupted by work. Unlike usual, he felt a flicker of annoyance.

"Who's calling you away this time?" Hisashi demanded. He was going to need to get the underworld under tighter control in order to prevent them from interfering with his love life.

Toshinori looked up. "Is it so obvious on my face? It's not a villain, actually. It's the HPSC."

"Ugh, what are those imbeciles up to this time?"

"They want to force everyone in Japan to enter their quirks into a database—which they'll be using to recruit children into the HPSC, track people who use their quirks in public even in small and harmless ways, and impose heavy restrictions on innocent people with quirks deemed dangerous."

"They have a lot of nerve," Hisashi hissed. His entire body shook with war flashbacks to the dawn of the age of quirks. During that brutal time when vicious mobs had hunted people like him for their hair color, a similar bill had been proposed. "They tried this nonsense once before and we showed them! If I have to create an earthquake to level the Diet building, I'll do it again!"

Toshinori gazed at him adoringly. "Whoa, I'm impressed at your history knowledge. Not many people know about the villain from the dawn of the age of quirks who destroyed the Diet building." He sighed. "But we have a bigger problem. Using some questionable methods to obtain access to private medical files, the HPSC found out that Izuku was once diagnosed as quirkless."

"How dare they?" Hisashi's voice dropped to an even lower growl. Those bastards had grown complacent because he'd been too busy fighting All Might to bring them to heel. Now that Hisashi had shifted priorities to doing things to All Might other than killing him, they'd find out what it would be like to receive the Lord of the Underworld's full attention.

"The HPSC has investigated me for years, and they've long been suspicious about the nature of my power." Toshinori's shoulders sagged. "They threatened to expose that Izuku has a transferrable quirk, unless I agree to support their vile bill. He'd be targeted by monsters who want to steal his power." Toshinori straightened. "I can't let this stand. The world doesn't need me any longer. It needs Izuku. I must protect him. I'm sorry, Hisashi. If I go to Tartarus for maiming the HPSC President, then please pretend we never dated so you're not affiliated with me."

"Stop, fool." Hisashi grabbed Toshinori's sleeve as he turned and headed for the door. "There's no need for that."

"Ah, you're always the voice of reason and compassion. But I must! I don't care if I go to prison!"

"We just have to be careful so they never tie the crime back to us." Hisashi smirked. "Together, we'll protect our boy."

Toshinori was gazing at Hisashi with that slack-jawed look again.

"What?" Hisashi asked. "Did I go too far for a hero?"

Toshinori said, "I think I just fell in love with you again."

Ahhhhhh, now Hisashi was blushing. How dare Toshinori make him blush? He preferred to do that to other people! Grabbing Toshinori by his collar and dragging him closer, Hisashi said, "Your murderousness turns me on. After we destroy our enemies, I'll show you how much." Ha, made Toshinori blush!

The news the next morning announced that the HPSC president had developed a mysterious wasting illness and was retiring. Several members of the Diet quietly left the country. The Diet announced a new bill reforming the HPSC. The quirk registry was never mentioned again.

Hisashi and Toshinori were too busy to watch the news. After staying up late last night, they both slept in. And since Hisashi hadn't gotten One for All last night, he insisted on trying again in the morning.

Several months later, after Izuku had started training with Gran Torino, Toshinori called his old mentor for a progress report. Eventually the topic turned to All for One.

Toshinori said, "I can't understand it. All for One seems to have completely vanished. League of Villains activity has ceased. Some of the villains popped up as independents, others left the business. It's as if his organization disbanded."

On the other end of the phone, Gran Torino harrumphed. "Do you think the ancient bastard finally died of old age?"

"That's a very real possibility." Toshinori sighed. "It's an anticlimactic outcome, but I'll take it just as long as he can't hurt anyone else."

"You're sure he's not just keeping a low profile and planning something?"

"Look, after hunting All for One for years, I'm an expert," Toshinori insisted. "I'm a hundred percent certain that All for One isn't anywhere in Japan, or I'd find him."

From the living room, Hisashi called, "Dear, I'm out of coffee."

"I have to go," Toshinori said into the phone. Then he ran into the living room to refill Hisashi's coffee and give him a shoulder massage.

With a sigh, Hisashi leaned into the touch. This was the good life. He'd finally found a wonderful partner who adored him as he deserved.

Thus the Lord of the Underworld quietly slipped into retirement. Eh, the world would be there later if he felt like conquering it.

OMAKE TIME!

Omake: Looney Tunes First Date

Toshinori: I'm hard to kill.

Hisashi: Because of my own weird love for danger, I find that attractive.

#

Omake: Compatible Schedules

Toshinori: I'm glad you don't mind when my work interrupts our dates. Actually, it's funny how often our work emergencies come up at the same time.

Hisashi: Yeah, I just need to be a kill a few more people and from there it will be smoother dates for both of us.

#

Omake: Stepdad Intentions

Toshinori: It's not the only reason, but if I marry Hisashi then I can be Izuku's dad.

Izuku: Aww, but you don't need to, you're already like a father to me.

Toshinori: Your dad is also hot.

Izuku: Ew, I didn't need to know that.

#

Omake: Second Best Again

Endeavor: Hey! You stole the title of number one most dysfunctional relationship from me.

Toshinori: I'm very confused.

Endeavor: Oh, now you're even stealing the title of number one in denial!

#

Omake: Genetics

Toshinori: Hisashi has the best hair.

Yoichi: Excuse me, you've only ever touched second place—you never met me!

#

Omake: The Ex's Blessing

Toshinori: Hisashi is the most genuine, kind person I've ever met.

Inko: You're being scammed, but taking my ex out of the dating pool is a true act of heroism.

#

Omake: A Convenient Misunderstanding

Hisashi: I hate All Might.

Toshinori: So you're saying that you like me for myself, Toshinori Yagi.

Hisashi: Not what I said, but if you buy me dinner again then I'll go with that explanation.

#

Omake: Favoritism

Toshinori: I love all my students equally, Midoriya and not-Midoriya.

Hisashi: See, this is why I only had one kid, so I didn't need to come up with such bad lies.

#

Omake: Possessive Villains

Toshinori: Gosh, I don't have any crazed stalkers these days. I guess they lost interest now I've mostly retired.

Hisashi: Sure, that's one explanation. On an unrelated note, I'm taking my car to get the trunk cleaned out. There's a lingering smell.

#

Omake: Mutually Influencing Each Other's Parenting

Hisashi: Izuku is putting himself in danger again! Where's my bank vault?

Toshinori: Love of my life, we've talked about this. Overprotectiveness will drive Izuku away.

Hisashi: Aargh. Can I at least kill my son's enemies?

Toshinori: I prefer to take villains alive.

Hisashi: Relationships require compromise. Just imagine some brute beating our sweet Izuku.

Toshinori: You've sold me. Where's my shotgun?

#

Omake: Visions from the Void

Yoichi: Listen to your dreams, Eighth, I'm trying to tell you something important! Namely, I'm trying to tell you that All for One is about to win against me in our unofficial contest for who can annoy each other the most with our romantic partners. That's what really matters here, more than the fate of Japan.

Toshinori: I hear nothing. All for One is a monster unable to love while Hisashi obviously adores his son. Therefore, no connection at all.

#

Omake: Excuses, Excuses

Hisashi: I slept with All Might once, but I didn't get One for All. I guess I'm going to have to keep trying. For the rest of my life.

#

Omake: Reactions from the Void

Nana: Well, that's one way to defeat All for One. Thanks to Toshi, All for One is no longer a villain and no longer a threat to Japan.

Second: It's not how I wanted to win, though.

Hikage: I feel like all of you scammed me by convincing me to hide in a forest for decades for this cause.

Banjo: Dude, you predominantly moved to the forest because you don't like people.

Yoichi: I'm just incredibly grateful All Might passed us over to Ninth before he started sleeping with my brother.

#

Omake: A Match Made in Tartarus

Toshinori: I'm on the asexual spectrum. In my case, I do enjoy sex, but I tend to be more a giver of pleasure than a receiver.

Hisashi: Excellent, because I'm definitely a taker.

Toshinori: Some people feel guilty if I don't let them reciprocate.

Hisashi: Not me! I never feel guilty about anything. I'd be completely happy with a relationship where you regularly give me blowjobs and I never, ever return the favor. I'll just lie on my back and let you do all the work.

Toshinori: You're perfect.

Hisashi: Yes, I am.

Author's Note: I only wrote this pairing as a prize for a fandom event, but now that I've finished, I can see these two working. Their dynamic is basically that All for One is horrible and All Might is the only one who can live with him. Thus the world is saved as long as All Might never finds out!