"Here, take this," ordered Katsuki.

What looked like a cage on wheels was pushed towards Shouto. He had been staring at the huge letters attached to the front of the building in front of him, reading and re-reading them and trying to decipher what they meant. When Katsuki pushed the wheeled object towards him, he panicked at the sight of it, immediately pushing it right back.

"What is that?" he questioned.

"What is th- Are you fucking serious?" Katsuki snapped in return. He grabbed the handle bar of the cart and wheeled it back over in Shouto's direction. "It's called a shopping trolley, you put your hands on here and push it. Think you can handle a task like that without setting anything on fire?"

His voice was dripping with condescending tones, but Shouto didn't notice.

"Yes. I can do that," Shouto said, taking hold of the handlebar with determination.

"Right…"

Shouto pushed the cart forward, the way he'd seen Katsuki do it, but found that it was a little less smooth than he was expecting it to be. As if not all of the wheels were moving at the same pace or in the same direction. Still, Shouto's upper body was strong from all those years of swimming and fighting. So, after a bit of an awkward start, he managed to get the shopping trolley to do what he wanted it to.

As they approached the doors, they opened on their own and Shouto almost left back in surprise, eyes wide. "Magic," he whispered to himself, astonished, as Katsuki walked on ahead without stopping. "The humans actually have magic."

"Oi!" Katsuki shouted, having noticed that Shouto had stopped. "What are you doing? Come on! We don't have the whole damn day for you to just stand around looking like an idiot!"

Shouto hurried to catch up with him, eyeing the doors warily as he passed through them. He thought he'd seen a lot of the things the human world had to offer, but he was quickly discovering that what he'd previously experienced had just been the tip of the iceberg.

When he took his eyes off the doorway and surveyed his surroundings, he let out an audible gasp. Food. As far as the eye could see there was food. Rows upon rows of it, to the point that the humans had sorted it into neatly labeled and numbered sections. And people were just walking up to it and taking it, putting it in carts like the one he was pushing or small metal baskets they were carrying in the crooks of their arms.

No one had to fight anyone or kill anything, there was enough for everyone and then some. He'd seen something like this on TV before, but actually being in this place and seeing it was another story. "Amazing," he said aloud, unable to stop himself. Katsuki shot him a questioning look, like he was being weird. Shit. "There's just so much stuff," he tried to explain.

Katsuki huffed out an incredulous sound. "Jesus Christ, anyone would swear that this was your first time going to a supermarket."

Shouto couldn't think of a rebuttal quickly enough, and Katsuki's smirk dropped into an expression of utter disbelief as he turned to face him.

"Shut the fuck up," he blurted.

"I didn't say anything."

"You've actually never been to a supermarket before, have you?" he questioned. Shouto shrugged in response, ducking his head a little at the shame of being caught out on his lack of knowledge and experience in the human act of shopping.

Katsuki let out a long, exasperated sigh. He placed one hand on his hip and pressed the fingers of his other to the patch of skin between his eyebrows, closing his eyes. He looked a little bit like the humans Shouto had seen in adverts for headache medication or like that angry blonde chef Shouto and Izuku were watching when someone didn't cook their meat well enough. What was his name again?

"This is gonna take so much longer than it should," Katsuki mumbled. "Should have fucking left you in the car."

"Do you need some headache tablets, Katsuki?" Shouto asked, slightly concerned that he was still in that pose. "I'm sure they might have some here if you need any."

"I don't have a fucking headache!" Katsuki snapped, before forcing himself to calm his tone when he saw how it made Shouto flinch in response. "I'm just stressed," he explained. "We don't have much time to fix things before the others get home, and I have a long shift at work tomorrow."

Shouto felt a sudden wave of guilt wash over him at the trouble he'd caused. Katsuki really shouldn't have to be going to all this trouble to fix things. Shouto's goal had been to make things easier for people, not more stressful. And he didn't know what a "shift" was, but it had to be something bad to have Katsuki so wound up, he didn't want to be giving Katsuki more things to worry about on top of that.

"I'm sorry, Katsuki," he replied, doing his best to get across how sincerely he felt it. "I didn't mean to cause you trouble."

Katsuki's tense posture deflated. "Don't be sorry," he argued. "just - look, we need to cover as much ground as we can as quickly as possible, so here's how we're gonna do it," Shouto listened intently as Katsuki took on a look of determination.

"First, we'll hit the vegetables, they're closest. And we may as well pick up some fruits while we're there since you decided to use all of them in that toxic waste you made."

Shouto was a little confused about what good hitting the vegetables was gonna do when they weren't exactly alive or likely to try and escape, but he wasn't gonna question a cooking expert. Maybe it was just a human tradition.

"Then we'll go to the meat and fish, then the dairy aisle, then pasta," Katsuki explained. "I think that will be enough for now. Oh, and we need to get sauce, but that will be in the same direction as the pasta. Ok, we got this, you just need to follow me and I'll grab the stuff we need. But you need to be speedy after the dairy aisle, I am not waiting around for you to free yourself from some mother hanging around the baby aisle. Think you can manage that?"

Shouto nodded, but then confusion took over his features.

"This place has babies?"

Katsuki didn't even give an answer to that question, he just sent an unimpressed look in Shouto's direction and started walking away. Shouto wheeled the cart after him, not wanting to cause any more hold ups when it was clear that Katsuki was on a mission to get out of there as soon as possible.

"Right, stop there," Katsuki instructed as he began selecting vegetables, inspecting them thoroughly before putting them in the trolley. "Shit. Izuku told me that he suspected you'd lived a sheltered life, but damn."

"My dad never let me go too far," Shouto confirmed, watching the items that dropped into the cart with interest. "I did sneak away when I could though."

Katsuki looked thoughtful as he motioned for Shouto to start following him again and they soon came to a display that had various different cuts of meat. Behind the display, Shouto could see people preparing more meat ready to go out. A little further up, he noticed that there was a similar set up for fish. It was still wild to believe that humans did this instead of having to fight for or even against their intended food, he wondered how they would survive if something ever happened to these places.

"Ok," he said, as he gave the meat the same scrutiny that he'd shown towards the fruits and vegetables. "But what do your parents even do if they've never taken you to the supermarket before? Was it like a 'they're too rich and powerful to do their own shopping' thing, a 'their jobs put them in too much danger to go out in public' thing or a 'you had a childhood illness and they were way too protective to let you go out' thing?"

Conversation with Katsuki was way more blunt and direct than Shouto had experienced with other humans. It was something he had to get used to after being around so many humans who tried to say what they were thinking without actually saying it to avoid being perceived as rude or acted as if they were kind and helpful when they had ulterior motives. But it was oddly reassuring to know that he would always know what Katsuki was thinking and if he was getting suspicious.

It was nice to know for certain that none of his trains of thoughts led to the conclusion that Shouto might not be human.

"Well, my dad was a royal guard and after I got my scar he didn't want people to see me because of our family's reputation so I guess a mixture of the three."

While scars were something celebrated on adult merpeople. Seeing a scar on a child was not good news. It gave the impression that the parents were incapable of protecting their offspring from danger. The shape of the scar wasn't good either, it didn't look like a battle scar, it looked exactly like what it was; a scar caused by magic. And mer society outcast those who had anything to do with magic.

So when Shouto had still been a child, his father had done his best to keep Shouto out of the public eye, waiting until he was a young adult to introduce him to mer society with the story that his facial scar had been something procured in a fight with a sea witch from foreign waters. The story had done its job in impressing people, but Shouto - having experienced the true version of events - had always felt resentful about the lie his father told and the way he seemed to see Shouto as a disappointment until he'd managed to create a version of him that other merfolk feared.

"That's rough," Katsuki replied.

"Yeah."

They moved on to the fish display and Shouto couldn't help staring in morbid fascination.

"Wait, I thought Izuku said you told him your dad was a fighter."

Shouto blushed, realising that he'd slipped up and revealed more than he should have. He was just glad royalty wasn't a foreign concept here or he really would have had some explaining to do.

"I thought Izuku would think I was strange if I told him the actual job title," he admitted sheepishly. "I said fighter because it's not entirely wrong, my dad does have to fight people."

Katsuki barked out a laugh. "You don't have to worry about that, all Izuku goes on about is how cool he thinks you are. It's gross. And the rest of us already think you're strange so at this point there's not much else that would surprise us."

They we're off to yet another aisle before Shouto had time to process that. For some reason it made him feel a little nervous, but in a good way. He barely even noticed that Katsuki had insulted him.

"Really?" Shouto asked as he rushed to keep up with the blonde guy.

Katsuki turned to roll his eyes at Shouto as he picked up a block of cheese and put it in the trolley. "Would ya focus for five minutes?" he asked, exasperated. "I don't need you getting all distracted when we have a job to do." He took a look at Shouto's expression. "Oh for the love of - yes, ok? For some damn reason that I can't fathom, Izuku really likes you. So you don't have to do all of this 'almost burning down his house trying to impress him' business."

Shouto felt like his face was burning up all of a sudden and he briefly hoped he wasn't getting some kind of odd human sickness. "I'm not trying to impress him," he muttered. "I was just trying to help."

Trying to impress was something reserved for courting rituals among his kind and that was not the way he intended to come across so soon with someone he had just met, especially after just getting out of another relationship. Merpeople usually stayed with the same partner their whole life. So the fact that his previous relationship hadn't lasted that long was confusing enough for him already without this added feelings of fondness for someone new.

"Yeah, well. Like I said, we're going to work out a way for you to do that later. So no more trying to cook without supervision, got it?"

If Shouto was a little less careful, he would have argued that his vision was actually pretty super and he didn't see how that would help him be better at cooking anyway. In fact, he was pretty sure his vision was much better than most humans considering that he'd previously had to be able to see in all kinds of conditions. He had a feeling that answer would make Katsuki angry though so he just nodded. In any case, he wasn't gonna try cooking again without someone there to watch him and give instructions when he needed them.

"Good," Katsuki responded, satisfied that Shouto was going to listen to him. "Now let's get to that pasta aisle and get out of here."

Once their cart was full, Shouto started heading back in the direction of the entrance, assuming Katsuki was following as he hadn't mentioned them needing anything else.

"Where the fuck do you think you're going?!" his voice called out frantically, stopping Shouto in his tracks.

Shouto turned to see him standing with his arms crossed back a few feet, next to a row of strange machines that appeared to be operated by humans, each one wearing the same outfit. Huh. He didn't know how he'd missed those earlier.

"You have to pay first, idiot! We can't just fucking work out with a bunch of food!"

Shouto tilted his head, an eyebrow raised in confusion, but still started to push the trolley back towards the other boy. "Pay?"

Katsuki sighed so loudly that he could hear it even as he approached.

"Yes, pay. Like that thing you do with money and credit cards," he explained, waving a slip of paper in front of Shouto's face.

Ah! Shouto had seen that before! He had seen humans swap those and small round metal pieces for things they wanted. How had he forgotten about that? It was a good thing Katsuki had reminded him, he didn't want to make the humans mad at him.

"Right, yeah. I know about paying," Shouto stated, and internally berated himself for how unconvincing it sounded even to his own ears.

Katsuki just started loading things onto the contraption that moved them towards the human with the machine. Shouto watched, captivated, as the human passed them through the machine and it made a beeping noise.

"What kind of rich family did you come from where they didn't teach you how to spend money?"

Shouto shrugged.

Katsuki rolled his eyes, shoving something white and plastic into his hands. "Just make yourself useful and go put stuff in this bag. Even you can't mess that up."

Suddenly it clicked in Shouto's head as he made his way to the other end where their food was coming out.

"Gordon Ramsay."

An item slipped out of Katsuki's hand back into the trolley as he shot up to glare at Shouto. "What?" he snapped. Shouto noticed a quiet smile grow on the face of the kind lady who was putting their shopping through the beeping contraption.

"That was the name of the angry chef on the TV who reminded me of you the other day."

The lady snorted out a laugh and quickly tried to cover it up as she passed a bag of pasta through to Shouto's side. Shouto could swear he saw Katsuki's eyebrow twitching.

"You're gonna regret saying that when we get back to the kitchen," he growled. "I'll show you fucking Gordon Ramsay."

A foreboding shiver went up Shouto's spine. Maybe he should have kept his mouth shut.

The rest of the payment process went fairly smoothly. Katsuki had to drag Shouto away after the human woman had thanked them for visiting and he felt the need to sincerely thank her back, and he had also nudged him out of the way and took the reins when he took too long to figure out where to return the trolley. But they were back in the car and putting on their seatbelts as Katsuki let out a relieved sigh relatively quickly.

"Thank you, for helping me. You didn't have to do that." Shouto said tentatively, not sure if it was what Katsuki would want to hear from him when their interactions before this day had not been particularly warm and friendly.

"Shut up, I know I didn't," Katsuki grumbled. Shouto smiled a small smile, knowing that was the closest Katsuki would probably get to saying he wanted to help. Then Katsuki smirked, and Shouto felt uneasy again.

"Besides, you shouldn't thank me yet. You still need to get through me teaching you how to cook an edible dinner."