Shinsou didn't have many friends. Not until he'd entered 1-A as a hero course student after their first Sports Festival.
The entire class seemed to be different somehow, and as they grew, and matured, that fact had never changed.
But Midoriya had a special place in Shinsou's heart, as one of the first kids his age, who heard what his quirk did and never even blinked between the knowledge and blurting "Oh my god, that's such a cool quirk!"
Over their years in class A, Shinsou had grown close to him, and enjoyed his company. He and Midoriya had a standing agreement every second Saturday of the month, to go out and try something new for one or both of them. (Not that it was the only time they hung out, but it was a left over from the days when Shinsou was jittery about having too many people around, and Midoriya wanted to be his friend.)
Shinsou had been talked into some stupid things over the years, including the time they had both stalked underground hero fights at 2am, or the time they had seen a guy use his quirk, and Midoriya was so excited they ended up trying to figure it out by following the guy and looking for clues.
Or the time that Midoriya had dragged him to Hero Con, and talked him into cosplaying Aizawa-sensei while Midoriya ran around as Present Mic. Which was how Shinsou learned Midoriya was a well known and respected name on hero forums and HeroTube. Incidentally- they had created quite a few videos ranging from 'conspiracy theories' to Midoriya's first time at a cat cafe, to the both of them trying new foods for the first time.
At any rate, Shinsou and Midoriya had done quite a few different activities over the years.
Today, they were supposed to head down to the corner store, and bring back movie snacks, so they could sit down and binge through a series of horror movies neither boy had ever seen, but Kaminari swore were worth watching.
Aizawa-sensei had driven them down to the corner- even as third years, all of 3-A had been targets of villains often enough that they weren't allowed to leave campus without an escort. Though they were trusted enough to be allowed to go into the store alone, and their provisional licenses ensured they could use their quirks if they needed to, Aizawa was still waiting inside the UA car in the parking lot, with the storefront in sight.
Shinsou had been laughing, shoving lightly at Midoriya's shoulder as they walked into the storefront.
It had been...unusually quiet, even for a corner shop.
It was instinct for the both of them to go quiet, searching for anything out of place. They glanced at each other, a silent moment of communication, and split up.
Carefully scanning the aisles showed the corner store was deserted.
When Shinsou and Midoriya met back up in the back of the store, they both looked uneasy.
"Something's wrong." Midoriya's voice was low, quiet as he scanned the store again.
"Yeah," Shinsou agreed "It's eerie."
Both boys headed towards the front counter. They hadn't seen anyone, but hoped to find some sort of explanation.
Shinsou wouldn't be able to tell anyone what made him lean forward, and look over the counter later on.
He'd just...done it.
And tucked into a corner, Shinsou could see terrified brown eyes staring at him from a woman tied up and pinned to the ground. His breath caught, and he immediately jumped over the counter, Midoriya a second behind him, as he spotted what had made Shinsou move.
Shinsou's hands were steady as he carefully began to untie her, and work the gag out of her mouth, as Deku began to carefully break the cement that had pinned her to the floor.
As soon as the gag was free, the woman began talking, fast and panicked "You have to get out!"
"Ma'am, everything is going to be okay-" Midoriya's voice was calm as he kept breaking the stone surrounding her legs, very careful not to hurt the woman in his efforts.
"NO!" the woman's voice was sharp and panicked, but determined. "No, you have to get out, my ex set the shop to explode you need to get away!"
Shinsou stilled, and saw Midoriya do the same, before he started breaking the cement quicker, but no less careful. "There were not explosions." Shinsou's voice was sure, as he spoke. They'd both gone over the store well, even poking heads into the rooms in the back that they technically didn't have access too.
The woman was crying, shaking her head "No- you wouldn't have seen anything. He can turn everything he touches into a timed bomb. His bombs aren't catastrophic on their own, but he's touched almost all of the things in the aisles before he left me here."
Shinsou and Midoriya met each other's eyes over her head, both worried and determined.
"Ma'am, can you tell me if there's any way to stop your ex's quirk? And his name, and the name of the person who did this to you?" Midoriya's voice was steady and calm, none of his worry showing.
The woman responded to their calm, Shinsou standing and running towards the place he had seen the video cameras while searching the store. He couldn't break the woman out, Midoriya would have to do that, but he could gather evidence.
There was a card access port in almost every security camera station, where a pro hero or provisional license could be used like an access card. Swipe the card, type in the proper password, and the contents of the camera(s) chosen by the hero would be sent to their agency for evidence. If it was found to be abused in any way, there would be consequences, and in the event the hero using their license to access security cameras owned their own agency that they worked at, they had to have another agency designated to receive the videos at the same time as their own, to make sure someone was checking this fact.
As soon as he had sent the evidence off, he rushed back to Midoriya and the woman, now free of her binds, and being lifted into Deku's arms.
Deku turned and pressed her into Shinsou's arms. "Take her outside to Eraserhead, and call the authorities. I'm going to start breaking things in here- according to Yumiko-san, it should stop her ex's quirk from activating if the items he touched are broken afterwards. She's not sure how long he set his timer for, so we have to be quick."
Shinsou wanted to scream.
He wanted to rage, he did not want to leave Deku behind in a building he knew was primed to explode, but not when. He wanted to start destroying things around him.
But Shinsou was a hero-in-training, and he knew he needed to get the civilian out of harms way before he could do anything about the 'exploding building' thing.
He took Yumiko-san from Izuku's arms, meeting his eyes over her head again. Izuku nodded once, seemingly picking up the nonverbal demand that he survive this, and Shinsou whirled around and rushed out of the store, making a beeline straight for Aizawa-sensei, who was already climbing out of the car, and pulling his yellow goggles into a more accessible position.
Shinsou retold the situation as quickly as he could, and before Aizawa could demand he stay outside, he rushed back towards the store.
He cleared the door, and watched the green sparks of Deku whirling around the store, bringing down shelves and shelves of product. Shinsou knew it would be quicker to start on the other side, and meet in the middle, but if the building exploded he wanted to be near to Deku when it happened, so he rushed towards him instead, joining in and pulling shelves down, and breaking everything he could get his hands on, his own capture weapon coming to life around his neck.
LINEBREAK
They destroyed most of the store in only a few moments.
They hadn't taken into account that the security camera computers were also an option, along with other items in the back room.
The building exploded with Shinsou and Midoriya both still inside.
Shinsou lunged for Deku, who lunged towards him as they both felt the wave of air pressure slam into them and send them careening back into the destroyed projects.
They were wrapped around each other, as the building started coming down on top of them.
(Later, it would be discovered that, by destroying the shelving and food products, Shinsou and Midoriya had actually saved several blocks of civilians, and instead of taking out the store and everything around it, they had limited the explosion down to just the store they were inside.)
That didn't make Aizawa feel any better when he watched the building collapse on top of both his students, stuck with the civilian until emergency services arrived. He could hear them approaching, but they had still been out of sight when the building collapsed down.
Aizawa was the first into the rubble once the paramedics had taken Yumiko-san off of his hands, and after he had called his students and alerted them to the situation. They were close by, and some of their quirks would be perfect for locating and extracting their other classmates.
(And if Aizawa hadn't told them, they'd have found out on the news, and it would have ended….much worse. At least this way he could direct the chaos that was 3-A, and give them something to do.)