I wish I had a name for this canon character (especially after she appeared again in canon…), but I left her as "the little girl" because I didn't want to make up a name lol
Todoroki Shouto is participating in a big mission... at least, it's supposed to be. A joint operation between several large agencies, including Endeavor's, made the mission sound far more interesting than it ended up being. Weeks of preparation in creating a safe meeting location for several VIPs, securing emergency exit routes, and screening everyone's background only to have the event be postponed. While no news is good news for their line of work, it is a bit disappointing when things fall apart because of a whim by one person (the most important VIP) at the last minute.
The higher ups argue about who takes the credit, responsibility, faults, and other things that Todoroki has absolutely zero interest in. No one is allowed to go home yet, but Todoroki makes the most of it as he exchanges secret messages with Yaoyorozu, his secret girlfriend who's agency is also participating, as they stand at attention. She is arguably the only saving grace that frees Todoroki from death by boredom.
…
Though still not allowed to go home, the interns, sidekicks, heroes, and general employees can go on break as long as they remain on standby at nearby locations. Todoroki and Yaoyorozu choose to stay at a public park right next to the meeting point as neither of them know the area very well.
They're sitting on a bench when Yaoyorozu asks to be excused for a second before standing and talking with one of her coworkers. Now alone momentarily, Todoroki takes the chance to find out whose gaze he's felt since a couple minutes earlier. It felt like it was coming from his back, so he turns his body to look behind the bench. He instantly identifies the source as a small child who looks familiar. She has light brown hair, which is tied up in a high, wavy ponytail and has a big grin on her face. "Five Wieners, it's you!"
While he's not especially fond of that nickname, it seems to have stuck with her and her classmates. At least the nickname lets Shouto finally recognize her as one of the students from the rowdy elementary class that he, Bakugou, Yoarashi, and Utsushimi were assigned to oversee for one of their remedial licensing classes.
Oh, this person is… He and Utsushimi were the older students that she talked to the most back then… which would make him look even worse if she found out that Shouto forgot her name. "Hello." He makes his way over and opens his mouth first in an attempt to mask that his mind is still coming up blank. "Good to see you again." He looks around and doesn't see any of her other classmates. "Is your school nearby?"
"Yeah! It's just a couple of blocks away. I live nearby, too."
"I see. That's good to know. Maybe I can ask your teacher if I can stop by and help out again."
"She'd like that a lot. And so would I!" The little girl then points her head at Yaoyorozu. "Is that your girlfriend?"
She's sharp. "No, she's just a classmate of mine."
"That's a shame. She's really pretty."
Todoroki has to fight a huge urge to agree.
"I've been a good girl at school. I've gotten high grades and even helped lead the class sometimes!."
"Good job."
"...That's it? Can you praise me more? Or could you head pat me?"
An innocent enough request. "Sure." He uses his right hand and gently pats her head. "I'm proud of you."
"Can I ask for one more favor?"
"What is it?"
"If you're not together with her," she gestures again at Yaoyorozu, "does that mean you're not together with anyone right now?"
Todoroki glances at Yaoyorozu for help on how to answer, but her back is turned so he can't tell if she's listening and knows the situation. In other words, I'm on my own. He ponders for a second before answering. "That's right."
"Then, if I continue being a good girl…" The little girl's cheeks flush. "Can we get married when I get older?"
"Huh?" Todoroki is completely clueless about how to respond. That makes him extremely happy to see his classmate make her way over to assist him in his time of need, as she always does.
"Unfortunately, he won't be able to do that." Yaoyorozu, who seems to have broken up her conversation midway based on the confused look of the person she was talking to, now interrupts.
"Hm? Why not?" The little girl asks. Todoroki is also curious about what Yaoyorozu is about to say.
"Because he'll be married to me by the time you're old enough."
…
"I thought we were supposed to keep it a secret?" Todoroki asks her while they sit together on the train on the way back to the dorms. They ended up being forced to stay for a little longer, but at least they have the whole train car to themselves.
"I'm ashamed of myself." Yaoyorozu covers her face with her hands. "I lost my composure from a grade schooler!"
He thinks back to how that earlier conversation could have gone much worse.
Yaoyorozu covers her own mouth when she realizes what she just said.
"Haha! I knew it!" The little girl laughs. "Still, it's not good to lie."
Neither of the recommended students can say anything in response.
"I told you that they could be wild. Even Bakugou got mad at them."
"...You make it sound like that's hard to accomplish."
"You're right. I don't know why I said that." Todoroki then pats her shoulder affectionately. "Don't worry, they won't spread it around. They're good kids at heart."
"I know. It's just… I couldn't keep it together when she suggested marriage."
"Even if we-" Todoroki points to himself and then her, "-weren't together, I wouldn't do that. It'd feel weird after knowing her from when she was in elementary school while I was in high school."
"Uh- well, I understand that. But there will be more people later on that ask you about marriage and dating- people closer to your age. People far more attractive than I-"
"No one's more attractive than you."
"T-thank you." She blushes. "I guess it's something I have to deal with until we let people know."
"Someone else is going to instantly snatch him up if you let him go."
Yaoyorozu finally removes her hand from her mouth. "...That won't happen."
"It might sound strange, but I feel happy that you reacted that way." He holds onto her hand for a second before pulling it away. "We could just choose to not hide it anymore."
"...Let me think about it for a little bit." Yaoyorozu then smiles at him. "Can I ask you something?"
"Of course you can."
"Where on earth did that 'Five Weenies' nickname come from?"
"From the capsules on my utility belt. They said they looked like wienies."
"That's adorable." Yaoyorozu chuckles. "A little vulgar, but adorable."
"Do you like it better than the 'Hand Crusher' nickname?"
She rushes to hide her head on his shoulder. "W-why did you have to remind me of that?" He takes comfort in being the only one that can hear her soft laughter.
He takes a quick glance at the window and sees they're almost at the next stop at a busy station. "Yaoyorozu, we're about to arrive at the next stop."
"Let me stay like this."
"I don't mind, but people are going to see?"
"We'll be discovered eventually." Yaoyorozu shifts her head into a more comfortable position. "I've decided; let's just start telling people about it. Then no one will care if they see us here. And we can stop hiding."
"Still…" Todoroki hums while thinking about earlier.
"Hm? What's wrong?"
"Marriage, huh?"
"...Please forget I said that." The look on his face makes her reconsider her words. "Okay, don't forget. But… would you mind if we postpone talking about that until we graduate?"
"No problem."
"Thank you. We have to tell everyone first." She clasps her hands together. "I'm sure they'll be surprised!"
...
"…Finally!" The girls all exclaim when Yaoyorozu tells them she and Todoroki are dating.
"What was that?" Yaoyorozu asks, not expecting this response in the least.
"Yaomomo..." Jirou sighs, "we knew for a long time. We were just waiting for you to tell us."
"You all knew already?"
"It's obvious when you start being affectionate when you think no one is looking. And believe me- sometimes, people were looking."
"Like when?" Yaoyorozu thinks back and the only times they were affectionate publicly were recently.
"You feed each other food." Ashido states matter-of-factly.
"I've seen you hold hands in the library, kero." Asui adds.
"There was also that time on movie night where he fell asleep on your shoulder and you let him stay there for like 10 minutes before waking him up." Uraraka says.
Yaoyorozu is embarrassed again at this lengthy breakdown. "Why didn't you say anything before?"
"No one said anything because we knew you were trying to keep it under the radar for whatever reason, but you two are absolutely terrible at hiding things. It was kind of exhausting to pretend that we didn't know." Ashido groans. "Now, we can finally tease you about it!"
"That was the worst kept secret I've ever seen." Jirou agrees.
"I didn't even know it was supposed to be a secret until a month ago." Hagakure chimes in.