Disclaimer: Of course I don't own My Hero Academia, its characters, or the franchise.
Story: Izuku ends up enjoying a fan convention, only to surprisingly run into and befriend none other than Sir Nighteye. Not that she knows that. Mirai on the other hand finally found a kindred spirit, albeit someone young. These two end up traversing a friendship full of fanboyism and fangirlism, all the while tip toeing around the awkward 'other' tension between them, even when All Might himself enters the equation…
Set as an AU genderbending fic, canon-rewrite.
Spoilers: Probably the whole series, at least up to the Overhaul arc.
Warnings: Age disparity, underage, cursing and sexual situations…
Pairings: Fem!Izuku/Sasaki Mirai (Sir Nighteye)

A Fan's Guide to Heroics
Chapter Seven: Friendships

"So you're heading out now?" Izuku asked, watching her older friend standing awkwardly by his car while still in her boxers and shirt, and inwardly giggling at how cute he looked.

He coughed lightly. "Yes, I will change at the office, since I have a spare change of clothes there. Thank you for lending me clothes, though I'm regretful that I had rushed out without the overnight bag I'd packed for last night in the first place."

She waved him off. "It's no problem. Thanks for taking care of me, Sasaki-san. I appreciate it and I'll make sure to set you up as my emergency contact, if you still don't mind. Being the closest person to me that's available and close by, it would make sense for you to be at the top anyhow."

"I'm more than okay with that," he replied softly, cupping the back of his neck. "I'm happy for you to trust in and rely on me so much. I promise I'll make sure to take that responsibility seriously."

The corner of her lips quirked up. "Don't be so serious, Sasaki-san. Besides, I know you will. Now…get going before you're late and you get in trouble."

For some reason, he chuckled and shook his head at that. "Don't worry, I won't," was the last he said before he climbed into his car and took off.

She smiled slightly to herself before she headed back into her warehouse, making her way up to her loft.

It had been nice having Mirai over —it hadn't been as awkward or tense as she thought it might be to have him stay over for the night and wake up with him in the morning. Izuku had actually really liked it and wouldn't have minded it happening in the future. And why not? She liked and trusted Mirai. They hadn't known each other that long really, but the way they've been together, it was like they'd been friends for a really long time and were so comfortable with each other that everything was just so natural and easy.

And, well, it had been nice waking up to being held like that.

Becoming a blushing mess, Izuku redirected her mind towards her workload and went for her laptop so she could do some of her online assignments.

When Mirai made it to his Agency, he parked quickly in his spot and then hurriedly made his way to the office floor, where he made a bee-line to his office and to the connecting room. He rummaged around his wardrobe for a new suit, ignoring how small and simple it was compared to the number of clothing racks and dressers Izuku had in her much larger bedroom.

Once Mirai had changed into a new suit, he went to the break room and started the coffee. He hesitated before looking through the kitchen to see what tea he had. Seeing just green tea, he brewed himself a cup and left the coffee for the others. He'd already started in on his day when Juzou came in and a little after was Awata. He didn't expect Mirio to come in until later, so he was surprised by the 2nd year coming in early.

"You're early today, Togata-kun. Something wrong?"

The blond gave him a sheepish smile. "Not wrong, just some help? You're really smart, Sir, so I thought you could help me with my math work."

Mirai paused but nodded in acquiesce. "I might be a bit rusty, but that's doable. May I see it?"

When Mirio handed him his homework, Mirai frowned in concentration while hiding his wince. He had tutored Mirio when he'd first taken him under his wing and had managed to bring him up to standards and gotten his grades up. And Mirai was actually rather proficient in math. It's just…

"This is pre-calculus," he furrowed his eyebrows. "Why're you doing this level of math already?"

As much work he'd put into Mirio's studies, he knew the other was nowhere ready to tackle this.

"Ah, Ectoplasm-sensei was handing bonus work for 2nd years. I thought I'd give it a try."

"Then very well. Come here, Togata-kun." Mirai looked over the problems with a careful eye. "I'm surprised you're wanting to do this work. Pre-cal is usually end of the year work for your year, if students wanted to keep going with math, which is usually only required for two years of high school. More advanced students can take Physics or Calculus third year, which is what Pre-Cal is required for."

Mirio hummed. "I know I'm not the smartest or anything. But I want to try my best and be able to show all the work Sir put into me."

Mirai felt warm and proud of his student. "Alright then. Let's get started."

Even still, they struggled through the problems together, skipping more than a few. Mirai was disappointed he couldn't help with more, especially after Mirio's heartfelt words. But…

"I have a friend who might be able to help," Mirai hedged. "Let me call her and ask."

He took out his phone, ignoring Mirio's curious gaze. "Midoriya-kun?" he greeted after hearing her answer cheerfully. "I was wondering if you could help with a few Pre-Cal problems for a student I'm helping?"

"Of course! Send me pics and I can solve them and then talk you through each one," she agreed easily.

"Thank you so much, Midoriya-kun," he said in relief. "I appreciate this."

He pulled up his camera and snapped a few pics before he sent them. Not too long after, she sent all of them back solved already.

"You can put me on speaker, if you want," she offered and he did so, putting his phone near Mirio.

He listened as she walked Mirio through each problem, with Mirai checking his work with the pictures she'd sent back.

"Thank you very much, Midoriya-sensei!" Mirio bowed towards Mirai's phone respectfully.

"Ah, it's okay, Mirio-kun. Let me know if you guys need more help! And no need to call me 'sensei', Mirio-kun!" She hung up and Mirai collected his phone.

While he was glad Mirio was able to finish, he admitted to being slightly jealous. Izuku had already started calling Mirio familiarly, while he was still 'Sasaki-san'. He wanted her to call him 'Mirai'...

"Sir, was that the friend you made at the convention? The same one who got you to watch anime at work?"

"Yes, the same one," Mirai admitted, though he was exasperated at Mirio's description.

"Wow, she's super smart, Sir!" Mirio said in admiration.

Mirai shared it. "She is," he agreed. "She does actually attend Tokyo University. She majors in Quirk Analytics, so if you ever want her to break down your Quirk…I was thinking of one day bringing her over," sometime after he'd finally let her know who he was.

"Sounds awesome! I can't wait to meet her."

Mirai nodded, thinking about her. He would have to start planning a way to reveal who he was to Izuku, especially since he really was eager to show off his work to her and to also finally let her know he wasn't a typical salaryman like she had immediately assumed (their first meeting came to mind and made him sweatdrop).

Idly, in the best case scenario, he let himself imagine her finding out he was Sir Nighteye and then her being embarrassed about everything she'd shown him and gushing over 'him' in front of him before —and then amusingly starting to fangirl right then and there…

It made him smile a little and think brightly of the future, not even noticing his student watching him in fond amusement.

The day was coming to a close and Mirai was pleased. Lots of things had been accomplished and he was looking forward to telling Izuku a watered down version of his day. Then his phone rang.

Expecting Izuku's number, even if it was early, he stopped short of answering when he saw and recognized the familiar number that he hadn't seen in a long time.

"Toshinori?"

"Ah, Mirai…long time no see."

Mirai clenched his armrest tightly, while the grip on his phone threatened to break it.

"Yes. Long time…no see," he had no idea what to say to him. A lot of things had been said or done between them and too much time passed. Of course he still cared about Toshinori and he'll always remain a fan of All Might. But things weren't the same and he doubted things could ever go back to the way things were.

"How have you been doing?" Toshinori's voice was light but careful.

"I'm…okay," Mirai answered awkwardly. "I've met someone actually," he found himself suddenly saying. "She's sweet and kind. I think you'd like her a lot."

'She's a huge fan of yours like me too,' he wanted to add. 'And she's beautiful and smart and I like her a lot. I want to see her everyday.'

But he and Toshinori weren't close enough anymore, not enough to share personal details to each other like they used to.

"That-that's good! I hope she's…that you're not…Look, Mirai, I hope she's not someone you're hoping that I pass One For All to —"

"No, I wasn't," he snapped back, irritated that that was what Toshinori had immediately assumed. "And even if I was, she's perfect in every way and would probably be perfect for it! She's really amazing and I adore her and I think I love —" he cut himself off, embarrassed at himself.

He cleared his throat. "I'm sorry for my outburst," Mirai said stiffly. "I hadn't meant to get so passionate."

"…No, that's alright. That was one of your best traits and I apologize for assuming."

Even if Toshinori's voice was contrite, Mirai was still heated and upset. "Anyway, was there anything you needed?"

"Principal Nedzu called. He offered me a teaching position."

"That's…nice?"

Relief that his old friend might finally take things easy and confusion as to why he'd called him to tell him that (or really, the first time they talk in years —minus the time Mirai called about Mirio —and this is what Toshinori called to talk about?).

"Did you put him up to it?"

He stiffened up, jaw clenching. "No, I did not." Mirai didn't want to talk anymore. "Excuse me, I didn't realize I had a prior engagement. I have to go."

He hung up then, taking a struggling breath as he closed his eyes. Of course things were like this between them.

Extremely upset, Mirai finished up at his Agency before he decided a drink was in order.

When Mirai woke up, his head was pounding and he was sprawled on his back on his bed. For a few seconds, he just wanted to lay there and die. He felt like he was dying. Mirai couldn't remember the last time he'd drank like that and dear God was he paying for it now.

An all too familiar head poked her head into his room, grinning at him.

"Good morning, Sasaki-san. Breakfast is ready."

"Thank you," he said dazedly, staring at Izuku before she left him. For a few seconds, he sat there processing her presence. Then his eyes widened and he rushed out of his room and then his office, still not seeing her. Remembering her talk of breakfast, he hesitantly went to the break room.

There, wearing only his button up, Izuku was quietly humming as she finished fixing up the table.

It was so domestic and she looked so good in his clothes. His clothes.

Muttering a quiet "Fuck", Mirai walked into the room more. "You don't…you don't have to do that," he said, feeling out of place.

After she placed the last plate down, she looked to him and smirked. "Don't tell me you're afraid of my cooking, Sasaki-san."

He glanced at the omelettes. "They look as good as they smell," he said honestly.

He sat down and she placed a cup of coffee next to him. "Thank you. And thank you for breakfast," he expressed his appreciation as she sat down next to him, well aware the both of them were more or less half naked. Speaking of their undressed state and her presence there…

"I was a bit surprised the bartender called me to pick you up," she said, revealing the start. "I hope you don't mind, but I used your car to drive you over here and it was really late so I also hope you don't mind me staying and borrowing your clothes to sleep in."

"Not…not at all," he said, trying to steady himself. "Thank you for taking care of me."

Izuku laughed. "All these thanks! I feel very appreciated."

He couldn't keep his eyes off of her. The idea of her in his clothes had haunted him since the night he'd stayed over and wore hers. Now, seeing her actually wearing his clothes, was branded into his mind. It made his attraction to her all the more obvious and he couldn't help being turned on by seeing her in his clothes.

"Eat up! It'll help your hangover, though if I knew where your aspirin was, I would've gotten you some."

He gave her a small smile. "It's fine. I have some in my office. Do you have somewhere to go today?"

"I have classes actually," she told him.

"I can drop you off," he quickly offered. "It's the least I can do."

Despite being completely embarrassed by everything and yet very turned on by the sight of her, he was still extremely grateful to her and also wanted to spend as much time as he could with her.

Izuku gave him a beaming expression. "I'd like that, thanks, Mirai-san."

He nodded before he froze, realizing what she'd just called him.

"'M-Mirai-san?'"

She gave him a playful grin. "Well, considering you were calling me Izuku all of last night and it's apparently what you saved my number under in your phone…" she teased, though she did wear a questioning look on her face.

Blushing slightly and rubbing the back of his neck, he could only just give her a sheepish look back.

"Mirai is fine, I-Izuku-kun."

Sometime after he'd driven her first to her student housing so she could take a quick shower and change, Mirai leisurely drove back to his Agency and headed to his room. Deciding on a quick shower himself, he went to his personal bathroom and got himself ready to clean up. Just as he was about to get into his shower, he glanced at himself in the mirror and went still.

Hair the same, contacts missing, and wearing his regular glasses…

Mirai had messed up and hadn't been wearing his disguise this whole time. From the moment she'd picked him up at the bar to the time he'd dropped her off at her school, he'd been just his normal self and a look she would clearly recognize as 'Sir Nighteye'.

There was no way she didn't know who he was now and he just wondered why she hadn't said a thing about it to him all morning.

Started 1/16/23 - Completed 1/31/23

A/n: Ohohoho, cat's out of the bag now, eh? But what to do, what to do? Anyway, sorry they came out so late when it's been done for a long while –like I mentioned in "Minutes to Heaven", I write a ton, but it takes more effort for me to edit and update XD I'll hope to do better once summer vacation comes around (well, that and I quit my job, so my last day is around then)!

Quick Points:

1. Aww, Nighteye's Fam are starting to enter into the picture more :)

2. Annnd then there's Toshi –well, their relationship is pretty strained still at this moment in time?

3. Sometime later on, things might get a little more explicit? How're you guys feeling about that being in the main story on Ao3 (regardless, FFN will be edited to suit guidelines)? Or prefer it being split off into a separate part and posted (it might ruin the flow the story though)? Let me know in the comments, so I can think about it!